(Kurz) W.E.Manning ex Steenis
Description
Engelhardia spicata var. integra (Kurz) W.E.Manning ex Steenis is a tree of the walnut family, Juglandaceae, native to the subtropical and warm-temperate forests of South and Southeast Asia. GBIF (around 136 occurrences) records the taxon from China, India, Indonesia, the Philippines, Thailand, Bhutan, Vietnam, Myanmar and Nepal, where it forms a component of broad-leaved hill and montane forest, often on forest margins and slopes. It typically occurs in the subtropical mid-montane belt; the tree photographed at Wangdi-Phodrang in Bhutan at 2,280 m in May represents it in early-season flower within this characteristic elevational zone.
Engelhardia spicata is a medium to large deciduous tree with pinnately compound leaves; in var. integra the leaflets are characteristically entire-margined (hence "integra"), distinguishing it from forms with toothed leaflets. The leaflets are opposite to subopposite along the rachis, elliptic to oblong, glabrous to thinly pubescent. The species is monoecious, with flowers borne in long, pendulous catkin-like spikes; the most striking feature is the fruit, a small nutlet subtended by a conspicuous, enlarged, three-lobed membranous wing (an accrescent bract) that develops into a samaroid structure adapted for wind dispersal, the spikes hanging in long tassels at maturity.
The genus Engelhardia (sometimes spelled Engelhardtia) belongs to subfamily Engelhardioideae of the Juglandaceae, a primarily tropical Asian lineage distinguished from the temperate walnuts and hickories by its winged, bract-derived fruits. The wind-dispersed samaras are an important diagnostic and ecological character, enabling the tree to colonise open and disturbed hill forest. As a widespread but variable species, E. spicata has been treated with several infraspecific taxa, of which var. integra is recognised on the basis of its entire leaflet margins.
Author: (Kurz) W.E.Manning ex Steenis · Sources: POWO (Kew), Flora of China Vol. 4, Flora of Bhutan Vol. 1, GBIF, Manning: The genus Engelhardia (Juglandaceae)