Compilation
Acrostichum siliquosum

C. thalictroides and C. cornuta have usually been distinguished by having the sterile fronds bipinnatifid or pinnatifid with crenate lobes respectively, the former being more or less East African and the latter West African. Schelpe in 1969 treated them as varieties, one from Sudan to Zimbabwe, Mozambique and Angola and the other from Senegal to the Cameroons but added that even varietal status might have to be given up. Pichi Sermolli (1957) was inclined to regard C. cornuta as a distinct West African species. He also considered C. gaudichaudii distinct with its sterile fronds only 6–8 cm long and narrowly divided, and fertile fronds 15–16 cm long. He had no doubt that all East African material was conspecific with Sri Lankan material and should be called C. thalictroides, and specifically states he had seen no material referable to C. cornuta. R.M. Lloyd has recently extensively reviewed the genus again and records both species from East Africa, but most specimens are referred to C. cornuta. The distinctions he gives are not convincing and many specimens have been annotated C. sp. aff. cornuta but this is I think an error for cf. cornuta when material is considered inadequate; it does not indicate that he thinks a third species occurs in East Africa. He has annotated Richards 10153 (Ufipa District, Kasanga, Kawa R., 18 June 1957) as C. thalictroides yet Last s.n. (Zanzibar) with 3-pinnatifid sterile fronds with narrow segments as aff. cornuta. He has also named one specimen from Sierra Leone and another from Mali as C. richardii Brongn., a South American species of identical facies but differing in having 16 spores per sporangium rather than 32. I have decided that all African material is best considered conspecific with the Asian C. thalictroides. Peter (F.D.-O.A: 18 (1929)) gives a reference (L.) Brongn. in Dict. Sci. Nat. 3: 350 (1816) but this is erroneous.Schelpe (1969) gives a full synonymy.