6. Castelnavia Tulasne & Weddell
Castelnavia Tulasne & Weddell, Ann. Sci. Nat. Bot. III, 11: 108 (1849).
Roots absent in C. princeps Tulasne & Weddell and perhaps also in other species; stems flattened, forked or lobed, firmly attached to rock. Leaves, unknown for some species, filiform and simple or forked, or lanceolate to fan-shaped and palmately lobed, the lobes ultimately divided into branched filaments. Spathellas ovoid becoming ± tubular when open with several teeth at apex, ovary usually remaining within spathella. Flowers numerous, borne in cavities on upper side of flattened stem, distinctly zygomorphic, shortly pedicellate; pedicel inflated above and asymmetrical, not elongating in fruit; tepals 2 or 3 (rarely none), alternating with and sometimes united to stamens; stamens 1--3, free or united at the base; filaments membranous, cohering with base of ovary; anthers dehiscing introrsely; pollen in monads. Capsules often at right angles to pedicel; valves very unequal, the smaller almost free from pedicel, caducous, either smooth or with 3 or 5 ribs, with or without papillae, the larger valve saucer-like, persistent, with 5, 7 or 9 ribs; stigmas linear, usually unequal in length, often longer than ovary at anthesis. Seeds relatively few. Nine spp., central Brazil, most confined to the Araguaya & Tocantins.