''Alfaroa'' is a genus of evergreen trees in the

Juglandaceae The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia. The nine or ten genera in the family have ...

family of the

Fagales The Fagales are an order of flowering plants, including some of the best-known trees. The order name is derived from genus ''Fagus'', beeches. They belong among the rosid group of dicotyledons. The families and genera currently included are as ...

, growing in montane and submontane tropical rain forests in Central America. The wood is characterized by solid pith, pink heartwood, and vessels with scalariform perforations, as well as simple perforations.

Description

The (usually

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

ly compound) leaves are evergreen and lack

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s. They are alternate, rarely opposite. The plants are monoecious, the male flowers being in lateral panicles (several pairs of catkins on an inflorescence) and the female flowers born terminally either in a single spike or in a hermaphroditic panicle including several paired male catkins. Each flower has a wide bract, two bracteoles, and four sepals. The flowers are sessile. The male flowers have a round or oblong receptacle and six to ten stamens. The pollen grains are approximately 24 micrometers in diameter and are slightly triangular in polar view. The small fruits are nuts, one-chambered at the apex and eight-chambered (sometimes four-chambered) at the base. Germination is

hypogeal Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface. In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remai ...

Species

''Alfaroa'' includes the following species (This list may be incomplete): * '' A. columbiana'', G. Lozano-C., J. Hernandez-C., & S. Espinal-T. * '' A. costaricensis'', Standl. —Campano Chile, Chiciscua, Gaulin, Gavilancillo * '' A. guanacastensis'', D. E. Stone * '' A. guatemalensis'', ( Standl.) L. O. Williams & A. Molina 1970 * '' A. hondurensis'', L.O. Williams 1959 * '' A. manningii'', Jorge Leon * '' A. mexicana'', D. E. Stone * '' A. roxburghiana'' ( Wall.) I. A. Iljinsk. * '' A. williamsii'', A. Modina R. ''A. guatemalensis'' and ''A. roxburghiana'' were originally described as belonging to the genus '' Engelhardia''. The monotypic genus ''Alfaropsis'' I. A. Iljinsk has also been erected for ''A. roxburghiana''.

References

Elliott, L. L., Mindell, R. A., & Stockey, R. A., "''Beardia vancouverensis'' Gen. et Sp. Nov. (Juglandaceae): Permineralized Fruits from the Eocene of British Columbia", ''American Journal of Botany'' 93(4): 557–565, 2006 Manchester, Steven R., "Fossil Wood of the Engelhardieae (Junglandaceae) from the Eocene of North America: ''Engelhardioxylon'' Gen. Nov.", ''Bot. Gasz'' 144(1)157-163, 1983. J. A. Vozzo (ed.) ''Tropical Tree Seed Manual'' "Part II—Species Descriptions", USDA Forest Service Engelhardioideae Fagales genera Neotropical realm flora Taxonomy articles created by Polbot {{Fagales-stub