4. Indotristicha P. Royen

Indotristicha P. Royen, Acta Bot. Neerl. 8: 475 (1959).

Roots thread-like, much branched, creeping, with finger- or disk-like holdfasts arising from same buds as shoots; vegetative stems totally submerged becoming discarded as the water recedes, arising from the root, branched, up to 60 cm long, bearing photosynthetic scales and ramuli (photosynthetic branchlets); ramuli up to 4 cm long, with scale-like to filamentous appendages arranged spirally or irregularly but never in 3 rows; flowering stems short,  each densely clothed in ramuli and scales; uppermost scales and ramuli united at their bases and forming a cupule (cup-like structure) of 5--7 scales and 1--3 ramuli at base of pedicel. Flowers solitary, terminal on short-shoots, pedicellate; tepals elliptic to ovate, united below; stamens 3; stigmas linear. Seeds ± 100 in I. ramosissima. Two spp., I. ramosissima (P. Wight) P. Royen and the poorly known I. tirunelveliana Sharma, Karthikeyan & Shetty, both from S India. Molecular data (Kato et al. 2003) indicate that Indotristicha ramossissima and Dalzellia zeylandica (Gardner) Wight are closely related.

Indotristicha ramosissima. A Vegetative shoot with some branches and ramuli removed (2 cm). B Fertile branch (2 mm). C Capsule (1 mm). D Fragment of vegetative shoot with one ramulus (2 cm).
Indotristicha tirunelveliana. E Tip of a flowering shoot with two ramuli (1 mm). F Capsule viewed from the side with three perianth segments attached (1 mm). G Capsule viewed from above (1 mm). H Ramulus with scales (1 mm).

Cook & Rutishauser 2007