20. Rhyncholacis Tulasne
Rhyncholacis Tulasne, Ann. Sci. Nat. Bot. III, 11: 95 (1849); van Royen, Med. Bot. Mus. Herb. Rijksuniv. Utrecht 107: 133--138 (1951), rev.
Roots thread-like to slightly flattened, perhaps 0 in R. carinata P. Royen, simple or branched; stems prostrate, flattened, often disk-like, merging into root and leaves. Leaf sheaths simple or double; petioles terete or slightly flattened, sometimes shortly winged; blades usually pinnate with forked lobes or palmate with lobes divided into filiform segments at tips; ultimate segments filamentous. Spathellas club-shaped or tubular, rupturing at apex. Flowers solitary or up to 20 in fascicles, arising from sheath pockets which often form cavities in the stem; pedicels (0.5--) 2--10 (--20) cm long; tepals 2--20 in a complete whorl, an incomplete whorl, or at one side of flower, some occasionally reduced to small teeth; stamens 2--30, in 1 or 2 whorls; filaments sometimes flattened at base; pollen in monads; anthers introrse. Capsules ellipsoidal to ovoid, laterally compressed; valves equal, each with 2 lateral ribs and a winged midrib; stigmas beak-like or clavate. Seeds numerous, up to ± 720 in R. penicillata Matthiesen. About 26 spp. (probably less when critically examined), N South America.