Aloe comosa
Encyclopedia
Aloe comosa is a species of plant
that is endemic to South Africa
.
, in the past it has been classified as being part of two different families: the Aloaceae or the Liliaceae
family. It wasn’t until 2003 that the APG II system
placed the genus in the family Asphodelaceae
, however some sources still classify aloe in either of the former families.
and Hermann Wilhelm Rudolf Marloth, whom specialized in South African botany and nomenclature of succulent plants. Even though Aloe comosa is indigenous to the Western Cape of South Africa, it is possible for experienced collectors and horticulturalists to maintain their plants outdoors, in Arizona and California for instance, or in a desert climate greenhouse.http://davesgarden.com/guides/pf/go/62868/
is involute. The morphology of its leaves are simple and have a lanceolate leaf shape that tend to curve towards the tips. The edges of the leaves are entire and are lined with spiny, tooth-like, brown-red thorns. The fleshy blades have a whorled leaf insertion as they emerge from the rosette
which sits on top of the erect stem.
Aloe comosa is considered a tree aloe having a single, unbranched stem which may attain heights of approximately 3 meters. As it matures and grows in height, Aloe comosa retains its dry, dead leaves and forms a tangled skirt or beard. Tree aloe bark differs from woody dicot bark in that it doesn’t have a phellogen, which is the meristematic tissue that differentiates into the bark. In essence, aloe bark is actually overlapping, irregular layers of incomplete bark tissues.
A study was published in the science journal Oecologia by W. Bond (1983) on the purpose of retaining dead leaves by several species of tree aloe. Researchers before Bond have set forth studies to try to understand the function of such an adaptation. A few suggestions were that dead-leaf retention protected bare bark from the sun during the day and the cold at night. On the contrary, another researcher believed that the thorny mass of leaves could deter unwanted wild life in search for water, nectar, or seeds. Bond, on the other hand, proposed that dead-leaf retention was selected to provide thick, fire resistant bark in a fire-prone habitat.
The seeds are produced in late February and early March of each year in time for the winter rains; the seasonal shift in the southern hemisphere is opposite that of the northern hemisphere. Once the seed capsules turn pale green, they will split and expose their flat, brown seeds. These seeds are enclosed by a thin, transparent membrane which aid in transporting the seeds. In the event of a sufficient breeze, the seeds are dispersed and blown some distance from the parent plant where they usually germinate under the protection of a nurse plant..
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
that is endemic to South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Name and Classification
Aloe comosa (Marloth & A. Berger) is the botanical name for what is commonly known as Clanwilliam aloe. Although Aloe comosa has always been a part of the genus AloeAloe
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"....
, in the past it has been classified as being part of two different families: the Aloaceae or the Liliaceae
Liliaceae
The Liliaceae, or the lily family, is a family of monocotyledons in the order Liliales. Plants in this family have linear leaves, mostly with parallel veins but with several having net venation , and flower arranged in threes. Several have bulbs, while others have rhizomes...
family. It wasn’t until 2003 that the APG II system
APG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...
placed the genus in the family 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...
, however some sources still classify aloe in either of the former families.
Background
Aloe comosa inhabits a very small region within the Western Cape province of South Africa. It was discovered in the Olifants River Valley in 1905, north of the town Clanwilliam (hence its common name). The person who discovered Aloe comosa has not been recorded but those that contributed its botanical name were two German botanists, Alwin BergerAlwin Berger
Alwin Berger was a German botanist best known for his contribution to the nomenclature of succulent plants, particularly agaves and cacti. Born in Germany he worked at the botanical gardens in Dresden and Frankfurt...
and Hermann Wilhelm Rudolf Marloth, whom specialized in South African botany and nomenclature of succulent plants. Even though Aloe comosa is indigenous to the Western Cape of South Africa, it is possible for experienced collectors and horticulturalists to maintain their plants outdoors, in Arizona and California for instance, or in a desert climate greenhouse.http://davesgarden.com/guides/pf/go/62868/
Characteristics
Typically, Aloe comosa has thick, succulent blades approximately 2 feet long. The leaf surface is glabrous and the curving of the laminaLeaf
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....
is involute. The morphology of its leaves are simple and have a lanceolate leaf shape that tend to curve towards the tips. The edges of the leaves are entire and are lined with spiny, tooth-like, brown-red thorns. The fleshy blades have a whorled leaf insertion as they emerge from the rosette
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:...
which sits on top of the erect stem.
Aloe comosa is considered a tree aloe having a single, unbranched stem which may attain heights of approximately 3 meters. As it matures and grows in height, Aloe comosa retains its dry, dead leaves and forms a tangled skirt or beard. Tree aloe bark differs from woody dicot bark in that it doesn’t have a phellogen, which is the meristematic tissue that differentiates into the bark. In essence, aloe bark is actually overlapping, irregular layers of incomplete bark tissues.
A study was published in the science journal Oecologia by W. Bond (1983) on the purpose of retaining dead leaves by several species of tree aloe. Researchers before Bond have set forth studies to try to understand the function of such an adaptation. A few suggestions were that dead-leaf retention protected bare bark from the sun during the day and the cold at night. On the contrary, another researcher believed that the thorny mass of leaves could deter unwanted wild life in search for water, nectar, or seeds. Bond, on the other hand, proposed that dead-leaf retention was selected to provide thick, fire resistant bark in a fire-prone habitat.
Reproduction
Naturally, Aloe comosa follows the typical angiosperm life cycle. Like most South African aloes, Aloe comosa blooms in the summer.http://aloegardenwilderness.blogspot.com/2006/12/summertime-blooms-with-small.html Tall inflorescences (flower stems) that can reach 2 meters in height branch from the rosette. At the tips of the inflorescences are flower spikes which are composed of many small, tightly compacted flowers. In most cases the color of the flower spikes ranges from rosy-cream to ivory-pink and is pale at the bottom of the spike with a darker pink hue on the upper parts. Pollination is carried out primarily by bees, although it is plausible that some evening moths could be pollinating this species as well.The seeds are produced in late February and early March of each year in time for the winter rains; the seasonal shift in the southern hemisphere is opposite that of the northern hemisphere. Once the seed capsules turn pale green, they will split and expose their flat, brown seeds. These seeds are enclosed by a thin, transparent membrane which aid in transporting the seeds. In the event of a sufficient breeze, the seeds are dispersed and blown some distance from the parent plant where they usually germinate under the protection of a nurse plant..