|Photo Dennis Stevenson
|The Cycad Pages
- Zamia hymenophyllidia D.W. Stev., "Fl. Colombia 21: 4344, fig. 6" (2001).
- "TYPE: Colombia, Amazonas, D. Cardenas et al. 10089(holo COAH; iso NY)."
The specific epithet is derived from the extremely thin almost
Zamia hymenophyllidia is most similar to Z. melanorrhachis.
Both species are unique in the cycads with the presence of extremely
long thin peduncles (to 30 cm long and 1-3 mm diam) terminated by very
small pollen cones (1-3 cm long and 1-3 mm diam). Zamia
hymenophyllidia has membranous, elliptic, long acuminate leaflets
in contrast to the papyraceous, lanceolate, generally acute leaflets
of Z. melanorrhachis. The leaflets margins of Z.
hymenophyllidia are generally entire and if toothed, the teeth
are inconspicuous and apical. In contrast, Z. melanorrhachis
has well-developed marginal teeth. Living plants of Z.
melanorrhachis have a dark purple to black petiole and
rachis, a feature not found in Z. hymenophyllidia.
Distribution and habitat:
Only three small populations are known in Southeastern Amazonian
Colombia. Zamia hymenophyllidia grows as an understory plant
in lowland primary rainforest.
Zamia hymenophyllidia was discovered only in the past three years from three small populations. The plants are reproductive and produce seeds and seedlings. Little is known about its biology and distribution but the paucity of collections indicates that it is rare. Not yet listed in
1997 IUCN Red List of Threatened Plants.
Stem subterranean and tuberous, 2-4 cm diam.
Cataphylls triangular basally, linear-lanceolate apically,
membranaceous, 2-3 cm long, 0.5-1 cm wide.
Leaves 2-5, erect, oblong, 30-70 cm long; petiole terete, to
35 cm long, armed with very small prickles; rachis terete, usually
unarmed, to 20-35 cm long, 4-10 pairs of leaflets.
Leaflets membranaceous, elliptic to elliptic-lanceolate,
long acuminate apically, cuneate to oblique basally, margins entire
or rarely with a few diminutive apical teeth, 12-15 cm long, 1-2 cm wide.
Pollen cones brown, ovoid, 1-3 cm long, 0.1-0.3 cm diam.;
peduncle 10-30 cm long; microsporophylls with both abaxial and a
few (1-3) adaxial sporangia.
Seed cones dark red-brown, cylindrical to ovoid- cylindrical,
to 5 cm long, 3-4 cm diam; peduncle to 15 cm long, 0.5 cm diam.
Seeds red orange-red, 1-1.2 cm long, 0.5-0.8 cm diam.