Barneby, Rupert C. & Krukoff, Boris A. 1971. Supplementary notes on American Menispermaceae. VIII. A generic survey of the American Tricilisisae and Anomospermeae. Mem. New York Bot. Gard. 22: 1-89.
Menispermaceae
Latin Diagnosis - A subsp. reticulato endocarpii testa tumuloso-rugulosa utrinque extus secus carinam dorsalem obscuram longitrorsus 1-seriatim foveolata intus lamellis validis (foveolis externis conformibus) armata absimihs.
Species Description - Leaf-blades (of subsp. reticulatum) glabrous or setulose beneath; reticulation of both faces moderately coarse, the larger areoles 0.3-0.4 mm diam; fruiting peduncles slender, 0.5-1 cm long, ±1.3 mm diam; drupe 2.8-3 cm long, gibbous below insertion of pedicel, like that of subsp. reticulatum except in sculpture, the exocarp ±1.5 mm thick, the endocarpic testa 1.5-2 mm thick, externally tumulose-wrinkled between the incised veinlets, charged around the long dorsal curve with 2 rows of shallow pits, these corresponding with rows of lamelliform teeth intruded into the cavity.
Distribution and Ecology - Distribution (3 collections): Known only from neighborhood of type locahty.
The subsp. idroboi cannot be distinguished from subsp. reticulatum until the drupe is sufficiently well formed to show the sculpture of the endocarp. The surface of the testa is not smooth between the incised veinlets but puckered up into rugose mounds and, along the long dorsal curve, impressed so as to form a row of shallow pits, these corresponding with a row of teeth projecting inward into the seed-cavity. The testa thus shares features of those of subsp. occidentale, which is wrinkled but lacks the pits, and of subsp. nitidum, which (also smaller) is pitted but smooth between the veinlets. Apparently a submontane derivative of subsp. reticulatum, which is confined to the Amazonian Hylaea, subsp. idroboi is to be looked for elsewhere along the east slope of the Andes.
According to the collector's notes subsp. idroboi is a high-climbing vine with flowers green in bud becoming yellowish-green at anthesis, and fruits at first dark green and shining becoming yellow when ripe.