Phoradendron dipterum

Primary tabs

Phoradendron dipterum

Content

Description

Glabrous, percurrent, often vigorous plants; internodes strongly compressed, to 8 cm long, some tending to be quadrangular or even 4-winged; lowest internodes of lateral shoots often keeled or more or less terete-quadrangular; basal cataphylls 1 pair, 0.3-0.5 cm above base, median in position, somewhat flaring when dry, rarely with a second pair somewhat higher. Leaf blade narrowly obovate to slightly spatulate, to 9(-13) x 3 cm, apex rounded, base tapering into 0.3-0.4(0.7) cm wide, flat, indistinct petiole, or somewhat amplexicaul; venation evident, of several basal, parallel veins nearly running into apex. Dioecious. Female inflorescence to 8.5 cm long, peduncle simple, 0.3-0.4 cm long, followed by about 6 fertile internodes; flowers 13-21 per fertile bract, 3-seriate. Fruit spherical, 0.2 x 0.2 cm, perianth segments closed.

Distribution

Argentina present, C Mexico present, Greater Antilles present, Southern America: Paraguay (Paraguay present), eastern Bolivia present, tropical America present
Tropical America, from C Mexico, Greater Antilles, to eastern Bolivia, Paraguay and Argentina; 250 collections studied (GU: 1; SU: 2).

Notes

P. dipterum is a member of a (perhaps always) hyperparasitic group of species which attack other mistletoes, often (but not exclusively) other species of Phoradendron. Its great variability of leaf size and stem morphology may be related to the different hosts parasitized, or perhaps to their vigor. The expression of the winged character of the stem varies not only from plant to plant, but even within a plant; the lowest lateral internodes are usually wingless, and elsewhere 2-winged and 4-winged internodes are sometimes found on the same individual. Another interesting feature of the group is the fact that secondary stems, lacking basal cataphylls, may sprout from a basal cushion, not found in other species.