Struthanthus

Content

Description

Scandent, glabrous parasites with terete or quadrangular stems; epicortical roots both at base of plant and on twigs. Leaves paired. Dioecious. Inflorescences solitary or clustered, axillary, an indeterminate spike or raceme of paired triads. Flowers 6-merous, inconspicuous and small, usually greenish white; prominent staminodia and vestigial styles representing aborted organs in female and male flowers, respectively. Fruit an orange, reddish or blue berry; endosperm white, embryo bright green, dicotylous. (x = 8).

Distribution

Guianas present, Southern America: Bolivia (Bolivia present), northern Argentina present, northern Mexico present

A strictly continental genus, ranging from northern Mexico, to Bolivia and northern Argentina; uncertain number of species (see note below); in the Guianas 4 species.

Chromosomes

(x = 8).1

1. 007

Notes

Struthanthus is believed to be polyphyletic, separate species or species groups being derived from distinct branches of Cladocolea. The genus is generally of low-altitude preference. It has never been monographed; the number of species, while uncertain, is at least 50.
Much confusion has existed in the past with regard to the separation of Struthanthus from Phthirusa, but the great majority of species of the former genus are easily recognized in the male plant by its versatile anthers. Uncertainty persists vis-à-vis the boundary of Struthanthus with Cladocolea, and with regard to certain small-flowered Phthirusa species like P. guyanensis and P. trichodes, which do not have the otherwise characteristic anther morphology of Phthirusa.
In the past, it was reported () that S. marginatus (Desr.) Blume occurs in Guyana. This appears to be incorrect, it is a Brazilian species, only encountered remote from the Guianas.