Key D: Key to the 2 subgenera of Ledermanniella

(according to Cusset 1983, 1984, 1987; combined and modified by R. Rutishauser)

1. Scale-like leaves (especially overlapping scales) lacking along the stems; all leaves usually elongate and forked with thread-like segments; when only scale-like leaves present, these leaves forming broad sheaths and arranged in 2 rows (distichous) along stems. Ledermanniella subgenus Ledermanniella (26 species, see Key E)

-- Overlapping (see footnote 1) scales (they may be called "imbricate scales" as well) (inserted all around the stem) and prominent main leaves (arranged in 2 rows) often develop on the same stem, at least towards the shoot tips. Main leaves simple, lobed or forked, linear with thread-like segments; overlapping scales with entire or toothed margins and sometimes with apical teeth. Ledermanniella subgenus Phyllosoma (20 species, see Key F and Key G)

Note: It is difficult and often impossible to identify the species of both subgenera when reproductive structures (flowers, capsules) are lacking. Ledermanniella subgenus Phyllosoma as defined by Cusset (1983) is characterised by often imbricate scales (teeth, enations, ...) which are inserted irregularly around the stem , i.e. not restricted to two opposite rows (orthostichies) along the stem. These scales are a unique character of subg. Phyllosoma . Other African Podostemoideae (including some members of subg. Ledermanniella ) with scale-like leaves have them arranged in two rows (i.e. distichously) along the stem. The scales of subgenus Phyllosoma are called "little leaves" ("feuillettes") in French (Cusset 1983). They are only 0.5 - 2 (rarely up to 5) mm long. Typical foliage leaves (also present in many members of subg. Phyllosoma, at least in young shoots) are arranged in 2 rows along the stem, and usually much longer (>1 cm), linear or forked into linear or thread-like segments. It seems that the scales provide excellent characters for species identification. Key E should allow to identify the species of subg. Ledermanniella , including the two recently decribed species L. prasina and L. onanai (Cheek 2003; Schenk & Thomas 2004). Two keys will be added below for the species of subg. Phyllosoma: Key F is a modified and version of Cusset's (1983) key. Key G gives more emphasis on the shape of the scales.

Footnotes

1 They may be called "imbricate scales" as well.