''Hevea microphylla'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of rubber tree in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Hevea ''Hevea'' is a genus of flowering plants in the spurge family, Euphorbiaceae, with about ten members. It is also one of many names used commercially for the wood of the most economically important rubber tree, '' H. brasiliensis''. The genus is n ...

'', belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Euphorbiaceae Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as '' Euphorbia paralias'', are herbs, but some, ...

. It is native to the Amazon basin where it occurs in Venezuela, Colombia and northern Brazil. It was first described in 1905 by the German botanist

Ernst Heinrich Georg Ule Ernst Heinrich Georg Ule (12 March 1854 – 15 July 1915) was a German botanist and plant collector. Biography He was born on 12 March 1854 in Halle an der Saale to science writer Otto Eduard Vincenz Ule (1820–1876). His brother was geograp ...

. It is the only member of the genus to be included in the subgenus ''Microphyllae''.

Description

''H. microphylla'' is a small tree up to tall, with a small, sparse crown and a slender trunk with a swollen, bottle-like base. It bears "winter shoots", stubby side shoots with short internodes, scale leaves on the stem and larger leaves near the tip. These poorly-developed shoots are short-lived, the foliage being shed before new shoots develop; this species shares this feature with '' H. benthamiana'' and '' H. brasiliensis'', the remaining trees in the genus being evergreen. The leaves have three leaflets which are bent back in the bud and are later held in a horizontal or deflexed position. The inflorescence develops in a leaf axle and consists of separate male and female flowers with five perianth lobes, with the female flowers near the panicle tip. These female flowers have a swollen

torus In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not tou ...

at the base and are the largest in the genus. The fruit is a capsule with three large seeds, each measuring around . It is yellow with green stripes and a red tip when ripe. In ''H. microphylla'', in contrast to other members of the genus, this capsule has thin, leathery valves and does not burst open when ripe to expel the seeds.

Distribution and habitat

''H. microphylla'' is an uncommon species

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the upper and middle reaches of the Rio Negro, a left-bank tributary of the Amazon River. It mostly grows on river banks or islands and the sandy or laterite soils it favours are heavily inundated by flood water for at least four months each year.

Uses

''H. microphylla'' is not exploited in the wild, probably because of the poor quality of the

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

which is mixed with

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on n ...

s, and it is not cultivated.

References

{{Taxonbar, from=Q15391503 Trees of the Amazon Trees of Brazil Trees of Colombia Trees of Venezuela Crotonoideae