Oreomunnea mexicana
Encyclopedia
Oreomunnea mexicana is a species of 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...

 in the family Juglandaceae
Juglandaceae
The Juglandaceae, also known as the Walnut Family, is a family of trees, or sometimes shrubs, in the order Fagales. Various members of this family are native to the Americas, Eurasia, and Southeast Asia....

, which grows in the tropical rain forests of Mexico, Guatemala, Nicaragua, Costa Rica, and Panama at altitudes from 1–1.7 km. Common names include Guayabo amarillo and Remiendo. The chromosome number is 2n = 32.

Synonymy

Engelhardia nicaraguensis Molina and E. mexicana Standl. are synonyms for O. mexicana subsp. mexicana.

Tree

O. mexicana grows to 30 m or more, up to 1.5m DBH
Diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....

, often with buttresses, and superficially resembles a walnut (Juglans sp.). The bark on a mature tree exfoliates (It does not on O. pterocarpa
Oreomunnea pterocarpa
Oreomunnea pterocarpa, known locally as gavilán or gavilán blanco is a species of Oreomunnea in the family Juglandaceae. It is found in Costa Rica, southeastern Mexico , and Panama ....

). The heartwood is pink. The pith is solid (not chambered, as in Juglans). The buds are protected by leaf primordia, with a fine coating of yellow scales (O. pterocarpa has glabrous primordia.

Leaves

The petioles of the opposite, coriaceous, pinnately
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...

 compound leaves are glabrous at the base (O. pterocarpa is hirsute). The petioles are short (less than 3.3 cm) as are the petiolules of the opposite leaflets (less than 3 mm). The leaflets, up to 1 dm in length, are 4-5 times as long as they are wide. The upper surface of the leaf is glaucous; the underside has a light yellow-brown peltate bloom.

Flowers and fruit

The inflorescences
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...

 are panicles
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....

, and may be androgynous (containing a single spike of pistalate flowers flanked by several staminate catkins), entirely staminate, or entirely pistalate. The fruit bears three wings on a globose nut, approximately 7 mm in diameter. Germination is hypogeal
Hypogeal
Hypogeal means "underground".* In botany, a seed is described as hypogeal when the cotyledons of the germinating seed remain non-photosynthetic, inside the seed shell, and below ground...

: the first two aerial leaves are pinately compound and opposite; for the next 3-6 dm, the leaves are placed alternately.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK