''Aspidostemon'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
s belonging to the family
Lauraceae
Lauraceae, or the laurels, is a plant family that includes the true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genera worldwide (Christenhusz & Byng 2016 ). They are dicotyledons, and occur ma ...
. It occurs in
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
.
Taxonomy
The genus was described by
Jens Gunter Rohwer &
Hans Georg Richter in ''Jahrbuch für Botanische Systematik, Pflanzengeschichte und Pflanzengeographie'' 109 (1): 74 in 1987. The
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
is ''
Aspidostemon perrieri'' (
Danguy) Rohwer.
The number of collections available is not large.
The identification was done at the Missouri Botanical Garden.
Description
They are shrubs or
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s up to 25 m high,
hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...
s. The leaves are entire, elliptical or narrowly elliptical. The fruit is a berry-like drupe dispersed mostly by birds. ''Aspidostemon'' species are no exception among the Lauraceae; they are trees with small flowers, hard to detect and collect and often overlooked or ignored when plants easier to collect or with showier flowers are at hand.
''Aspidostemon'' is characterized by its opposite leaves,
flowers with three or six stamens (compared to 9 in ''Cryptocarya''), and a fruit which is completely enclosed in the enlarged hypanthium with persistent floral parts attached to the top of the fruit.
When the genus was described by Rohwer & Richter in 1987, they recognized 11 species, but today 28 species are accepted. Some species are endangered or almost extinct.
Based on a combination of wood anatomical, vegetative, and floral characters, noted by such earlier botanists as Kostermans in 1957, the species of genus ''Aspidostemon'' were placed formerly as belonging to subgenera ''
Hexanthera'' and ''
Trianthera'' of''
Cryptocarya
''Cryptocarya'' is a genus of evergreen trees belonging to the laurel family, Lauraceae. The genus includes more than 350 species, distributed through the Neotropical, Afrotropical, Indomalayan, and Australasian realms.
Overview
The genus inc ...
''.
Ecology
''Aspidostemon'' species have the large trees characteristic of rainforest in
montane
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
laurel forest
Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elo ...
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
s in
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
and nearby islands and restricted to this region. They belong to an ancient isolated
Gondwanian element of
Laurales
The Laurales are an order of flowering plants. They are magnoliids, related to the Magnoliales.
The order includes about 2500-2800 species from 85-90 genera, which comprise seven families of trees and shrubs. Most of the species are tropical and ...
. A great number of species are in danger of extinction due to
overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...
as
timber extraction
Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars.
Logging is the beginning of a supply chain ...
and
loss of habitat
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
.
They are leafy canopy trees with erect or spreading branches. They grow to heights of up to 25 m, or some species to 40 m. Their stout
trunks are up to 1 m in diameter. The genus is easily recognizable by its bark which is soft and cheese-like.
The thick, leathery leaves are dark green. The leaves are glossy
laurel type.
The leaves of ''Aspidostemon'' species are not infrequently acuminate, with an acumen folded into a short tube. On opening a few of these inrolled apices, egg cases similar to those found in leaf domatia are found; epiphyllous hepatics were also found. These inrolled apices apparently function as domatia and shelter mites that clean the leaves.
The fruit is an important food source for birds, usually from specialized genera. Birds eat the whole fruit and regurgitate or defecate the seeds intact, expanding the seeds in the best conditions for germination (
ornitochory). In some species,
seed dispersal
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant.
Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...
is carried out by
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s.
Accepted species
29 species are currently accepted:
[''Aspidostemon'' Rohwer & H.G.Richt.]
''Plants of the World Online'', Kew Science. Accessed 28 August 2022.
*''
Aspidostemon andohahelensis''
van der Werff
*''
Aspidostemon antongilensis''
van der Werff
*''
Aspidostemon apiculatus''
van der Werff
*''
Aspidostemon capuronii''
van der Werff
*''
Aspidostemon caudatus''
Rohwer
*''
Aspidostemon conoideus''
van der Werff
*''
Aspidostemon dolichocarpus''
(Kosterm.) Rohwer
*''
Aspidostemon fungiformis''
van der Werff
*''
Aspidostemon glandulosus''
Rohwer
*''
Aspidostemon grayi''
van der Werff
*''
Aspidostemon humbertianus''
(Kosterm.) Rohwer
*''
Aspidostemon inconspicuus''
Rohwer
*''
Aspidostemon insignis''
van der Werff
*''
Aspidostemon lacrimans''
(Kosterm.) Rohwer
*''
Aspidostemon litoralis''
van der Werff
*''
Aspidostemon longipedicellatus''
van der Werff
*''
Aspidostemon lucens''
van der Werff
*''
Aspidostemon macrophyllus''
van der Werff
*''
Aspidostemon manongarivensis''
van der Werff
*''
Aspidostemon masoalensis''
van der Werff
*''
Aspidostemon microphyllus''
van der Werff
*''
Aspidostemon occultus''
van der Werff
*''
Aspidostemon parvifolius''
(Scott Elliot) van der Werff
*''
Aspidostemon percoriaceus''
(Kosterm.) Rohwer
*''
Aspidostemon perrieri''
(Danguy) Rohwer
*''
Aspidostemon reticulatus''
van der Werff
*''
Aspidostemon synandra''
Rohwer
*''
Aspidostemon trianthera''
(Kosterm.) Rohwer
*''
Aspidostemon trichandra''
van der Werff
References
{{Taxonbar, from=Q4808044
Lauraceae genera
Endemic flora of Madagascar