Pachypodium brevicaule
Encyclopedia
Pachypodium brevicaule is a species of plant that belongs to the dogbane family Apocynaceae
, which is now amplified by the inclusion of the milkweed family Asclepiadaceae
-- an important union to botanists and horticulturalists interested in the alliance succulents.
, from the south of Antananarivo to the Itremo Mountains.
-like plant with a very low trunk
and a very wide, exaggerated diameter without substantive branching whatsoever with exception to several extremely short flattened "branch"-like nodes or rosettes
of leaves
.
Western forest
of Madagascar in full sun on sandstone
, rarely on granite
, in crevices between outcrops of quartzite
. With a pH. Level
varying from 3.5 to 4.5, it is strictly adapted to growing in acid
substrate
s. (That strictness to acidity seemingly has implications to its cultivation.) It is found in the evergreen
Sclerophyllous (Uapaca
) woodland
or savanna
zones dominated by scattered woody plants. It grows at altitude
s of 1250–1900 m (sometimes 2000 m).
Associated plant species
, site indicators, include Pachypodium densiflorum, P. eburneum (Apocynaceae
), Aloe
compressa, A. capitata, (Asphodelaceae
), Euphorbia quartzicola (Euphorbiaceae
), (Orchidaceae
), (Graminaea), (Bryophyta
), and Lichen
es.
It occurs in a region that receives an annual rainfall of 1354 mm with a number of 5 dry months
. Average monthly temperature
s varies from 9 °C to 17 °C. The yearly average temperature is higher; however, at 13 °C to 18.4 °C.
in habit. It is considered a dwarf plant. It takes on a broad flattenened tuberous, cactus-like habit that has a very short trunk measuring 2 to 8 cm high and an exaggerated diameter that can reach 10 to 40 cm. When in flower
the plant gains stature by reaching a height of 25 cm. Pachypodium brevicaule Baker barely, if all, "branches." Rather it seems to form protruding nodes or rosettes
of leaves that ranch from 1 to 4 cm in length and 2 to 4 cm in width. In the "Botanical Key for the Genus Pachypodium," the character "without branches or branchlets" is a distinguishing morphological
character to the species Pachypodium brevicaules definition.
The bark
is colored pale grey and is sometimes shiny. It has a smooth texture. The bark is about 2 to 4 mm thick, with the wood
being greenish. The "branches" or, better said, nodes of rosettes of leaves, when fresh, have paired, rather soft, curved spine
s at their apices, measuring 2 to 9 mm long by 1 to 1.5 mm at the base. They are pale grey to pale brown. When young, they are pubescent and more or less flat.
, without a stem
, petiolate
--with a stalk
--peduncle
--the main axis of the inflorescence
--or pedicel
--the stalk of a single flower--or it is shortly petiolate--having a stalk. If it has a stalk, the petiole
measures up to 2 mm long. It is sparsely pubescent, fuzzy.
The leaf blade is herbaceous
, not woody-like, and glaucous
, covered in a very fine bloom
or a fine powdery layer, when fresh and papery when dried. The blade is shaped ovate, broad and rounded at the base and tapering toward the end, to obovate, egg-shaped and flat with the narrow end attached to the stalk. It measures 11 to 30 mm in length by 6 to 12 mm in width. The apex of the blade is acuminate, narrowing to a slender point. The base is blunt or rounded. The blade of Pachypodium brevicaule Baker is glabrous, smooth, to sparsely pubescent, slightly hairy, on both sides, with impressed venation above, and with midrib and secondary veins prominent beneath. There are 15-30 pairs of secondary veins, which are straight at the base, upcurved at the apex, and forming an angle of 45-85° with the costa, or the midrib of a leaf. The tertiary
, third-level, venation are reticulate, forming a web or a network like pattern.
, with a stalk, or pedunculate, with the main axial stem to an inflorescence. It can be congested with up to 7 flowers where the inflorescence measures 2.5 to 15 cm in length by 2 to 6.5 cm in width. The peduncle, itself, is glaucous and covered in a fine bloom. It takes the shape of a terete, an elongated cylindrical form that is round in cross-section. The terete measures roughly up to 120 mm in length by 2 to 4 mm in width. The degree of pubescent varies on the peduncle from sparsely to fully hairy, pubescent. The pedicels, the stalk of a single flower, measures up to 8 mm long and is hairy, pubescent.
The bract
s, modified leaves at the base of a pedicel of a flower, a peduncle, or a branch, are longer than the pedicels on Pachypodium brevicaule Baker. They are narrowly oblong, having a somewhat elongated form with approximately parallel sides, to obovate, egg-shaped and flat with the narrow end attached to the stalk. The bracts measure from 5 to 13 mm long by 1.5 to 3 mm wide.. At their apex, they are acuminate, tapering gradually to a sharp point, or acute, having a sharp point or tip. On the outside, the bracts are fully pubescent, hairy to slightly so. Inside they are less so.
part of the corolla tube, the petals of a flower considered as a group or unit and usually of a color other than green, or the inner whorl of the perianth
shaped like a tube. The sepals are connate
, united to a structure of the same kind, i.e. other sepals, at the base for about 0.5 mm. They are narrowly ovate, broad and rounded at the base and tapering toward the end, or narrowly oblong, having a somewhat narrowly elongated form with approximately parallel sides. The sepals measure 6 to 11 mm long by 2 to 3 mm wide. At the apex, they are acuminate, tapering gradually to a sharp point, or acute, having a sharp point or tip. Outside the sepals are often glabrous and smooth; whereas inside in the lower part and near the apex, they are slightly pubescent, hairy.
and forms a comparatively wide broadly ovoid, shaped like an egg, ovate, head measuring 7 to 11 mm long by 5 to 8 mm wide. The apex of the bud is obtuse
, having a blunt or rounded tip. Overall the bud is pubescent outside. The corolla lobes are not as hairy; however. Especially where the lobes and tubes are covered in bud, the surface is glabrous. The pubescent belt inside the corolla tube is 2 mm above to 1 mm below where the stamens are inserted, not emerging beyond the corolla tube. Otherwise the corolla tube is glabrous and smooth. It is shaped like a funnel, infundibuliform, at 12 to 18 mm long (1.63 times as large as the calyx and 1.05 to 1.36 times as long as the lopes) The basal of the corolla tube is almost cylindrical. It is 2 to 3 mm long by 2 to 2.5 mm wide above the base (0.15 to 0.18 times the entire length of the entire tube.) The upper part of the corolla tube is almost cylindrical. Yet it widens at the throat altering the cylindrical form. The upper part measures 10 to 15 mm long by 5 to 5.7 mm wide at the mouth. The lobes are obliquely obovate, having sides of unequal length or form, which are egg-shaped and flat with the narrow end attached to the stalk. At their apex, the lobe of Pachypodium brevicaule Baker are rounded. They measure 9 to 18 mm in length by 8.5 to 14 mm in width. (That is, in proportion, the lobes are 0.73 to 0.94 times as long as the corolla tube and 1.1 to 1.3 times as long as they are wide.)
of the corolla tube, are inserted, meaning they do not extent beyond the corolla tube or mouth of the flower. They measure from the base 3.5 to 4 mm. (Proportionally they are 0.22-0.29 of the length of the corolla tube.) The stamens are the "male reproductive" organ of an angiospermous flowering plant.
The anthers, the part of the stamen, typically on top, which bears the pollen, commonly consisting of (1) two of four theca
e, which contain the pollen
and (2) a sterile
region in between the connective that is very narrowly triangular. The anthers range in size for Pachypodium brevicaule from 4.7 to 5.2 mm long by 0.7 to 0.9 mm wide. (Proportionally, that is, they are 5.22 to 7.14 times as long as wide.) Inside, the anthers are pubescent and hairy at the base of the connective, the part of tissue in a stamen that separates the two thecae of an anther. As well, it is pubescent just below where stamens cohere with the pistil head, the fertile region of the flower.
Pubescent and hairy, the ovary
measures ovary 1.5 to 1.9 mm long (x) by 1.3 to 1.6 mm wide (y) by 1.2 mm high (z). The disk in a pistil is the slightly thickened, or otherwise distinguished region, around the style in certain flowers that secret nectar. The disks of Pachypodium brevicaule Baker number 5 broad ovate glands that are broad and rounded at the base and tapering toward their end. These glands, for which either 2 or 2 pair can be partly fused together, are about half as long as the ovary. (Proportionally that 0.5 times 1.5 to 1.9 mm.).
The often cylindrical stalk-like portion connecting the stigma with the carpel or ovary, the style is slightly pubescent and hairy at the base for the taxon
. The stigma is the top-most receptive region of the style, which often divided into stigma-lobes that are commonly wet by a sticky exudate that helps captures and nourish pollen grains. The carpel, furthermore, is the female organ of the angiospermous flower that consists of a modified leaf that contains the ovules. Several carpels can be fused together to from a compound ovary.
The slightly pubescent style for Pachypodium brevicaule measures 2.6 to 3.6 mm long. The pistil head, the separate part attached to the style, is 0.71 to 1.0 mm high. It composition is complex. Its basal part is 0.4 to 0.6 mm long by 0.4 to 0.6 mm wide. The central part is ring-shaped at 0.15 to 0.2 mm in length by 0.5 by 0.7 mm in width. And, its stigmoid apex measures 0.1 to 0.15 mm long by 0.3 to 0.5 mm wide.
Each carpel contains approximately 50 ovules.
" fruit, that becomes dry at maturity and subsequently splits or breaks into several smaller pieces--i.e. individual mericarp or seed. The mericarps are colored pale to dark brown with longitudinal lines outside and whitish inside when dried. The fruits are fusiform at 57 to 140 mm long (x) by 3 to 5 mm wide (y) by 2 to 4 mm high (z). They are obtuse, having a blunt or rounded tip, to acute, having a sharp point or tip, at the apex. The surface of the fruit is pubescent and hairy. The exterior wall is 1 mm thick.
, which is a scar on a seed indicating the point of attachment to the funiculus
, the stalk connecting a seed with the placenta. The seed measures 3.5 to 3.9 mm in length by 1.5 to 1.8 mm in width. The testa, the outer and normally hard and protective layer of the seed, is smooth. The coma of Pachypodium brevicaule Baker is straw-colored at 13 to 21 mm long. A coma is usually terminal tuft of hairs on a seed. In the case of Pachypodium, the coma allows the seed to be airborne, as that is its means of distribution.
Whereas the embryo
measures 3.2 to 3.5 mm in length, the cotyledons are 1.5 in length by 1.5 mm in width. The cotyledons are ovate in shape, meaning that they are broad and rounded at the base and tapering toward the apex. They are cordate, having a heart shape, at the base. The rootlet is 2 to 2.5 mm long by 1.2 mm wide. (Proportionately that is 1.3 to 1.6 times as long as cotyledons)
John Gilbert Baker published Pachypodium brevicaule in 1887 in Journ. Linn. Soc. Bot. 22: 503 (1887).
In 1934, J. M. H. A. Perrier de la Bâthie published an account of the taxon in Bulletin de la Société Botanique de France. 81: 303 (1934).
Pichon, in 1949, offers another account of Pachypodium brevicaule Baker in Mém. Inst. Sc. Madag. sér. B, 2: 122 (1949).
The latest account, before Rapanarivo et al. is provided by Friedrich Markgraf within, Fl. Madag. fam. 169: 299 (1976).
The Species Type
is: Madagascar, sin. loc., Baron 4412 (holotype
The Herbarium of the Royal Botanical Garden at Kew
, near London
; isotype
The Herbarium of the Laboratoire de Phanérogamis at Paris
). Fig. 3, p. 18; Map 2, p. 12; Plates 8-10, opposite p. 17.
----
Apocynaceae
The Apocynaceae or dogbane family is a family of flowering plants that includes trees, shrubs, herbs, and lianas.Many species are tall trees found in tropical rainforests, and most are from the tropics and subtropics, but some grow in tropical dry, xeric environments. There are also perennial herbs...
, which is now amplified by the inclusion of the milkweed family Asclepiadaceae
Asclepiadaceae
According to APG II, the Asclepiadaceae is a former plant family now treated as a subfamily in the Apocynaceae...
-- an important union to botanists and horticulturalists interested in the alliance succulents.
Distribution
This plant is native to MadagascarMadagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, from the south of Antananarivo to the Itremo Mountains.
Habit
A flattened, tuberous, cactusCactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...
-like plant with a very low trunk
Trunk (botany)
In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the...
and a very wide, exaggerated diameter without substantive branching whatsoever with exception to several extremely short flattened "branch"-like nodes or rosettes
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...
of leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
.
Ecology
Pachypodium brevicaule Baker grows in open, deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
Western forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
of Madagascar in full sun on sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
, rarely on granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
, in crevices between outcrops of quartzite
Quartzite
Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...
. With a pH. Level
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
varying from 3.5 to 4.5, it is strictly adapted to growing in acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
s. (That strictness to acidity seemingly has implications to its cultivation.) It is found in the evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
Sclerophyllous (Uapaca
Uapaca
Uapaca is a genus of plant, in the family Phyllanthaceae and is the only genus comprised in the subtribe Uapacinae. It comprises about 60 species, of which 49 are confined to continental Africa.-Synonyms:This genus is also known as:...
) woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
or savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
zones dominated by scattered woody plants. It grows at altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
s of 1250–1900 m (sometimes 2000 m).
Associated plant species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, site indicators, include Pachypodium densiflorum, P. eburneum (Apocynaceae
Apocynaceae
The Apocynaceae or dogbane family is a family of flowering plants that includes trees, shrubs, herbs, and lianas.Many species are tall trees found in tropical rainforests, and most are from the tropics and subtropics, but some grow in tropical dry, xeric environments. There are also perennial herbs...
), Aloe
Aloe
Aloe , also Aloë, is a genus containing about 500 species of flowering succulent plants. The most common and well known of these is Aloe vera, or "true aloe"....
compressa, A. capitata, (Asphodelaceae
Asphodelaceae
Asphodeloideae is a subfamily of the monocot family Xanthorrhoeaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae. The subfamily name is derived from the generic name of the type genus, Asphodelus...
), Euphorbia quartzicola (Euphorbiaceae
Euphorbiaceae
Euphorbiaceae, the Spurge family are a large family of flowering plants with 300 genera and around 7,500 species. Most are herbs, but some, especially in the tropics, are also shrubs or trees. Some are succulent and resemble cacti....
), (Orchidaceae
Orchidaceae
The Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species,...
), (Graminaea), (Bryophyta
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
), and Lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
es.
It occurs in a region that receives an annual rainfall of 1354 mm with a number of 5 dry months
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
. Average monthly temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s varies from 9 °C to 17 °C. The yearly average temperature is higher; however, at 13 °C to 18.4 °C.
Habit
Pachypodium brevicaule is unique to the genusGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in habit. It is considered a dwarf plant. It takes on a broad flattenened tuberous, cactus-like habit that has a very short trunk measuring 2 to 8 cm high and an exaggerated diameter that can reach 10 to 40 cm. When in flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
the plant gains stature by reaching a height of 25 cm. Pachypodium brevicaule Baker barely, if all, "branches." Rather it seems to form protruding nodes or rosettes
Rosette (botany)
In botany, a rosette is a circular arrangement of leaves, with all the leaves at a single height.Though rosettes usually sit near the soil, their structure is an example of a modified stem.-Function:...
of leaves that ranch from 1 to 4 cm in length and 2 to 4 cm in width. In the "Botanical Key for the Genus Pachypodium," the character "without branches or branchlets" is a distinguishing morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
character to the species Pachypodium brevicaules definition.
The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
is colored pale grey and is sometimes shiny. It has a smooth texture. The bark is about 2 to 4 mm thick, with the wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
being greenish. The "branches" or, better said, nodes of rosettes of leaves, when fresh, have paired, rather soft, curved spine
Thorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
s at their apices, measuring 2 to 9 mm long by 1 to 1.5 mm at the base. They are pale grey to pale brown. When young, they are pubescent and more or less flat.
Leaves
Pachypodium brevicaule has leaves that are confined to the apices of the branches or nodes and rosettes. The leaves are sessileSessility (botany)
In botany, sessility is a characteristic of plants whose flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel...
, without a stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
, petiolate
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
--with a stalk
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
--peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
--the main axis of the inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
--or pedicel
Pedicel (botany)
A pedicel is a stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower....
--the stalk of a single flower--or it is shortly petiolate--having a stalk. If it has a stalk, the petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
measures up to 2 mm long. It is sparsely pubescent, fuzzy.
The leaf blade is herbaceous
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
, not woody-like, and glaucous
Glaucous
Glaucous is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the Glaucous Gull , Glaucous-winged Gull , Glaucous Macaw , and Glaucous...
, covered in a very fine bloom
Bloom
Bloom or blooming may refer to:-Science and nature:* Bloom, one or more flowers on a flowering plant* Algal bloom, a rapid increase or accumulation in the population of algae in an aquatic system...
or a fine powdery layer, when fresh and papery when dried. The blade is shaped ovate, broad and rounded at the base and tapering toward the end, to obovate, egg-shaped and flat with the narrow end attached to the stalk. It measures 11 to 30 mm in length by 6 to 12 mm in width. The apex of the blade is acuminate, narrowing to a slender point. The base is blunt or rounded. The blade of Pachypodium brevicaule Baker is glabrous, smooth, to sparsely pubescent, slightly hairy, on both sides, with impressed venation above, and with midrib and secondary veins prominent beneath. There are 15-30 pairs of secondary veins, which are straight at the base, upcurved at the apex, and forming an angle of 45-85° with the costa, or the midrib of a leaf. The tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
, third-level, venation are reticulate, forming a web or a network like pattern.
Inflorescence
The inflorescence of Pachypodium brevicaule is sessileSessility (botany)
In botany, sessility is a characteristic of plants whose flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel...
, with a stalk, or pedunculate, with the main axial stem to an inflorescence. It can be congested with up to 7 flowers where the inflorescence measures 2.5 to 15 cm in length by 2 to 6.5 cm in width. The peduncle, itself, is glaucous and covered in a fine bloom. It takes the shape of a terete, an elongated cylindrical form that is round in cross-section. The terete measures roughly up to 120 mm in length by 2 to 4 mm in width. The degree of pubescent varies on the peduncle from sparsely to fully hairy, pubescent. The pedicels, the stalk of a single flower, measures up to 8 mm long and is hairy, pubescent.
The bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s, modified leaves at the base of a pedicel of a flower, a peduncle, or a branch, are longer than the pedicels on Pachypodium brevicaule Baker. They are narrowly oblong, having a somewhat elongated form with approximately parallel sides, to obovate, egg-shaped and flat with the narrow end attached to the stalk. The bracts measure from 5 to 13 mm long by 1.5 to 3 mm wide.. At their apex, they are acuminate, tapering gradually to a sharp point, or acute, having a sharp point or tip. On the outside, the bracts are fully pubescent, hairy to slightly so. Inside they are less so.
Flowers
The sepals of Pachypodium brevicaule's flower are glaucous, having a fine bloom over the surface. This bloom covers the basalAnatomical terms of location
Standard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
part of the corolla tube, the petals of a flower considered as a group or unit and usually of a color other than green, or the inner whorl of the perianth
Perianth
The term perianth has two similar but separate meanings in botany:* In flowering plants, the perianth are the outer, sterile whorls of a flower...
shaped like a tube. The sepals are connate
Connation
Connation in plants is the developmental fusion of organs of the same type, for example, petals to one another to form a tubular corolla. This is in contrast to adnation, the fusion of dissimilar organs.-Terms for connation of flower parts:...
, united to a structure of the same kind, i.e. other sepals, at the base for about 0.5 mm. They are narrowly ovate, broad and rounded at the base and tapering toward the end, or narrowly oblong, having a somewhat narrowly elongated form with approximately parallel sides. The sepals measure 6 to 11 mm long by 2 to 3 mm wide. At the apex, they are acuminate, tapering gradually to a sharp point, or acute, having a sharp point or tip. Outside the sepals are often glabrous and smooth; whereas inside in the lower part and near the apex, they are slightly pubescent, hairy.
Corolla
The corolla, the inner whorl of the perianth, is bright yellow. It measures 17 to 25 mm long in the mature budBud
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specialized to develop flowers or short shoots, or may have...
and forms a comparatively wide broadly ovoid, shaped like an egg, ovate, head measuring 7 to 11 mm long by 5 to 8 mm wide. The apex of the bud is obtuse
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
, having a blunt or rounded tip. Overall the bud is pubescent outside. The corolla lobes are not as hairy; however. Especially where the lobes and tubes are covered in bud, the surface is glabrous. The pubescent belt inside the corolla tube is 2 mm above to 1 mm below where the stamens are inserted, not emerging beyond the corolla tube. Otherwise the corolla tube is glabrous and smooth. It is shaped like a funnel, infundibuliform, at 12 to 18 mm long (1.63 times as large as the calyx and 1.05 to 1.36 times as long as the lopes) The basal of the corolla tube is almost cylindrical. It is 2 to 3 mm long by 2 to 2.5 mm wide above the base (0.15 to 0.18 times the entire length of the entire tube.) The upper part of the corolla tube is almost cylindrical. Yet it widens at the throat altering the cylindrical form. The upper part measures 10 to 15 mm long by 5 to 5.7 mm wide at the mouth. The lobes are obliquely obovate, having sides of unequal length or form, which are egg-shaped and flat with the narrow end attached to the stalk. At their apex, the lobe of Pachypodium brevicaule Baker are rounded. They measure 9 to 18 mm in length by 8.5 to 14 mm in width. (That is, in proportion, the lobes are 0.73 to 0.94 times as long as the corolla tube and 1.1 to 1.3 times as long as they are wide.)
Stamens
The stamens of Pachypodium brevicaule, with an apex of 4 to 9 mm below the mouthMouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
of the corolla tube, are inserted, meaning they do not extent beyond the corolla tube or mouth of the flower. They measure from the base 3.5 to 4 mm. (Proportionally they are 0.22-0.29 of the length of the corolla tube.) The stamens are the "male reproductive" organ of an angiospermous flowering plant.
The anthers, the part of the stamen, typically on top, which bears the pollen, commonly consisting of (1) two of four theca
Theca
A theca refers to any case, covering, or sheath.In botany, the theca of an angiosperm consists a pair of microsporangia that are adjacent to each other and share a common area of dehiscence called the stomium. Any part of a microsporophyll that bears microsporangia is called an anther. Most...
e, which contain the pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
and (2) a sterile
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
region in between the connective that is very narrowly triangular. The anthers range in size for Pachypodium brevicaule from 4.7 to 5.2 mm long by 0.7 to 0.9 mm wide. (Proportionally, that is, they are 5.22 to 7.14 times as long as wide.) Inside, the anthers are pubescent and hairy at the base of the connective, the part of tissue in a stamen that separates the two thecae of an anther. As well, it is pubescent just below where stamens cohere with the pistil head, the fertile region of the flower.
Pistil
Composing the female reproductive organ, the pistil varies in length from 4.8 to 6.5 mm.Pubescent and hairy, the ovary
Ovary (plants)
In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule and is located above or below or at the point of connection with the base of the petals and sepals...
measures ovary 1.5 to 1.9 mm long (x) by 1.3 to 1.6 mm wide (y) by 1.2 mm high (z). The disk in a pistil is the slightly thickened, or otherwise distinguished region, around the style in certain flowers that secret nectar. The disks of Pachypodium brevicaule Baker number 5 broad ovate glands that are broad and rounded at the base and tapering toward their end. These glands, for which either 2 or 2 pair can be partly fused together, are about half as long as the ovary. (Proportionally that 0.5 times 1.5 to 1.9 mm.).
The often cylindrical stalk-like portion connecting the stigma with the carpel or ovary, the style is slightly pubescent and hairy at the base for the taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
. The stigma is the top-most receptive region of the style, which often divided into stigma-lobes that are commonly wet by a sticky exudate that helps captures and nourish pollen grains. The carpel, furthermore, is the female organ of the angiospermous flower that consists of a modified leaf that contains the ovules. Several carpels can be fused together to from a compound ovary.
The slightly pubescent style for Pachypodium brevicaule measures 2.6 to 3.6 mm long. The pistil head, the separate part attached to the style, is 0.71 to 1.0 mm high. It composition is complex. Its basal part is 0.4 to 0.6 mm long by 0.4 to 0.6 mm wide. The central part is ring-shaped at 0.15 to 0.2 mm in length by 0.5 by 0.7 mm in width. And, its stigmoid apex measures 0.1 to 0.15 mm long by 0.3 to 0.5 mm wide.
Each carpel contains approximately 50 ovules.
Fruit
The fruit of Pachypodium brevicaule has two separate mericarps that form an angle of 5-45° at its base. Sometimes it is possible to see flowers on the same inflorescence that has fruit. Mericarps are the parts of a "schizocarpSchizocarp
A schizocarp is a dry fruit that develops from multiple carpels. When mature it splits up into mericarps. Mericarps are often 1-seeded as in, for example, Malva, Malvastrum, and Sida...
" fruit, that becomes dry at maturity and subsequently splits or breaks into several smaller pieces--i.e. individual mericarp or seed. The mericarps are colored pale to dark brown with longitudinal lines outside and whitish inside when dried. The fruits are fusiform at 57 to 140 mm long (x) by 3 to 5 mm wide (y) by 2 to 4 mm high (z). They are obtuse, having a blunt or rounded tip, to acute, having a sharp point or tip, at the apex. The surface of the fruit is pubescent and hairy. The exterior wall is 1 mm thick.
Seeds
The seed of Pachypodium brevicaule Baker is pale brown. It is shaped in an elliptical manner. Its margin has a distinct broader that is revolute, rolled backward from the tip or margins to the undersurface, towards the hilar. The hilar pertains the hilumHilum (biology)
In botany, the hilum is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus...
, which is a scar on a seed indicating the point of attachment to the funiculus
Ovule
Ovule means "small egg". In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument forming its outer layer, the nucellus , and the megaspore-derived female gametophyte in its center...
, the stalk connecting a seed with the placenta. The seed measures 3.5 to 3.9 mm in length by 1.5 to 1.8 mm in width. The testa, the outer and normally hard and protective layer of the seed, is smooth. The coma of Pachypodium brevicaule Baker is straw-colored at 13 to 21 mm long. A coma is usually terminal tuft of hairs on a seed. In the case of Pachypodium, the coma allows the seed to be airborne, as that is its means of distribution.
Whereas the embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
measures 3.2 to 3.5 mm in length, the cotyledons are 1.5 in length by 1.5 mm in width. The cotyledons are ovate in shape, meaning that they are broad and rounded at the base and tapering toward the apex. They are cordate, having a heart shape, at the base. The rootlet is 2 to 2.5 mm long by 1.2 mm wide. (Proportionately that is 1.3 to 1.6 times as long as cotyledons)
Literature
Pachypodium brevicaule BakerJohn Gilbert Baker published Pachypodium brevicaule in 1887 in Journ. Linn. Soc. Bot. 22: 503 (1887).
In 1934, J. M. H. A. Perrier de la Bâthie published an account of the taxon in Bulletin de la Société Botanique de France. 81: 303 (1934).
Pichon, in 1949, offers another account of Pachypodium brevicaule Baker in Mém. Inst. Sc. Madag. sér. B, 2: 122 (1949).
The latest account, before Rapanarivo et al. is provided by Friedrich Markgraf within, Fl. Madag. fam. 169: 299 (1976).
The Species Type
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
is: Madagascar, sin. loc., Baron 4412 (holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
The Herbarium of the Royal Botanical Garden at Kew
Kew
Kew is a place in the London Borough of Richmond upon Thames in South West London. Kew is best known for being the location of the Royal Botanic Gardens, now a World Heritage Site, which includes Kew Palace...
, near London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
; isotype
Isotype
Isotype can refer to:* In crystallography, an "isotype" is a synonym for isomorph* In biology, per the International Code of Botanical Nomenclature, the "isotype" is a duplicate of the holotype....
The Herbarium of the Laboratoire de Phanérogamis at Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
). Fig. 3, p. 18; Map 2, p. 12; Plates 8-10, opposite p. 17.
External sources
- Eggli, Urs. (1993) Glossary of botanical terms with special reference to Succulent Plants. with German Equivalents (British Cactus & Succulent Society: United Kingdom)
- Rapanarivo, S.H.J.V., Lavranos, J.J., Leeuwenberg, A.J.M., and Röösli, W. Pachypodium (Apocynaceae): Taxonomy, habitats and cultivation "Taxonomic revision of the genus Pachypodium," S.H.J.V. Rapanarivo and J.J. Lavranos; "The habitats of Pachypodium species" S.H.J.V. Rapanarivo; "Cultivation" W. Röösli. (A.A. Balkema: Rotterdam, Brookfield, 1999) [Rapanarivo et al.]
- Wiktionary: Terms
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