Cotyledon (genus)
Encyclopedia
Genus
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...
of the Crassulaceae
Crassulaceae
Crassulaceae, or the orpine family, are a family of dicotyledons. They store water in their succulent leaves. They are found worldwide, but mostly occur in the Northern Hemisphere and southern Africa, typically in dry and/or cold areas where water may be scarce...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
. Plants in the genus occur in the Arabian peninsula and throughout the drier parts of Africa, but mainly in Southern Africa.
Members of the genus are shrublets, generally succulent, with fleshily woody, brittle stems and persistent succulent leaves. The leaves are opposite. Leaf pairs generally are oriented at 90 degrees to their preceding and following pairs, as is common in the family Crassulaceae, but the leaf habit differs from say Tylecodon
Tylecodon
Tylecodon is a genus of plants in the family Crassulaceae. Until the late 1970s all these plants were included in the genus Cotyledon, but in 1978 Dr Helmut Toelken of the South Australian Herbarium split them off into a genus of their own...
in which the leaves are borne in spirals and are deciduous.
The flowers are pendulous and tubular, borne at the tips of stout, rather long 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...
s, mainly in short cyme
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...
s. Calyx
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
5-partite, corolla
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
5-lobed. Petals united in a tube or urn
Urn
An urn is a vase, ordinarily covered, that usually has a narrowed neck above a footed pedestal. "Knife urns" placed on pedestals flanking a dining-room sideboard were an English innovation for high-style dining rooms of the late 1760s...
that generally is longer than broad, their triangular tips more or less pointed and recurved, 10 stamens arising from corolla near base and projecting or nearly projecting from the corolla. Gynoecium
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
comprises 5 carpels, nearly or quite free, each carpel tapering into a slender style
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
with an obliquely capitate stigma
Stigma (botany)
The stigma is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower. The stigma receives pollen at pollination and it is on the stigma that the pollen grain germinates. The stigma is adapted to catch and trap pollen with various hairs, flaps, or sculpturings...
. Each carpel contains many small (typically less than 1 milligramme when ripe) globular, brown seeds
Until the 1960s there were about 150 species described as being in the genus Cotyledon. However, since then it has been split into at least Adromischus
Adromischus
Adromischus is a genus of easily propagated leaf succulents from the Crassulaceae family.Adromischus are endemic to southern Africa.The name comes from the ancient Greek "adros" et "mischos" .- Species :* Adromischus alstonii...
, Dudleya
Dudleya
Dudleya is a genus of succulent perennials, consisting of about 45 species in southwest North America.Many plants in the Dudleya genus were formerly classified as Echeveria....
, Rossularia, and Tylecodon
Tylecodon
Tylecodon is a genus of plants in the family Crassulaceae. Until the late 1970s all these plants were included in the genus Cotyledon, but in 1978 Dr Helmut Toelken of the South Australian Herbarium split them off into a genus of their own...
, leaving probably less than two dozen species in Cotyledon. Of these, about four are characteristically fynbos
Fynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
plants.
Most plants in the genus, as well as those that formerly were included in the genus Cotyledon, are poisonous, even dangerously poisonous. Some have been implicated in stock losses among goats, pigs and poultry. However, many species have long been used in traditional medicine. They have been applied for many purposes, ranging from magic charms to removal of corns (allegedly successfully). One thing that is clear is that the species vary in their activity, ranging from allegedly edible to deadly, so it is best to regard all species as dangerous until otherwise demonstrated.
As succulents go, Cotyledons certainly are rewarding garden and indoor subjects, practically independent of irrigation in all but full desert conditions, though they cannot survive poor light or bad drainage in the wet. Their main enemies are sucking bugs, members of the suborder Homoptera
Homoptera
Homoptera is a deprecated suborder of order Hemiptera; recent morphological studies and DNA analysis strongly suggests that the order is paraphyletic. It was therefore split into the suborders Sternorrhyncha, Auchenorrhyncha, and Coleorrhyncha....
such as Mealy bug (Pseudoccus and similar insects. Though not spectacular, they are elegantly decorative and often interesting in shape. The inflorescences of the larger species often make fine components of dried arrangements in Floral design
Floral design
Floral design is the art of using plant materials and flowers to create a pleasing and balanced composition. Evidence of refined floristry is found as far back as the culture of Ancient Egypt....
.
Species include:
- Cotyledon adscendens
- Cotyledon barbeyi
- Cotyledon campanulata
- Cotyledon cuneata
- Cotyledon chrysanthaCotyledon chrysanthaCotyledon chrysantha is an ornamental plant of Crassulaceae family....
- Cotyledon elisae
- Cotyledon galpinii
- Cotyledon orbiculataCotyledon orbiculataCotyledon orbiculata, commonly known as Pig's Ear or Round-leafed Navel-wort, is a succulent plant belonging to the Cotyledon genus.-Description:...
– Pig's Ear, Round-Leafed Navel-Wort - Cotyledon papilaris
- Cotyledon tomentosaCotyledon tomentosaCotyledon tomentosa is a species of the Cotyledon genus. Cotyledon tomentosa, native to Africa, has large chunky ovate fuzzy green leaves with prominent "teeth" at tips that give the impression of bear's paws. It forms large orange bell-shaped flowers in spring...
- Bear's Paw - Cotyledon undulata - Silver Crown, Silver Ruffles
- Cotyledon velutina
- Cotyledon woodii