Notes on Malesian grasses VII. Chikusichloa, Digitaria

Among collections recently (1979) made in the surroundings of Kutacane, Aceh, N. Sumatra, by Mr. and Mrs. De Wilde, a grass has turned up which proved to be a species of Chikusichloa Koidz., a genus sofar known only from South China, Japan, and the Ryukyu Islands. As this is a very interesting find and since the genus is new for the Flora Malesiana area, a few notes seem appropriate. Chikusichloa was originally described in the Paniceae by Koidzumi (1925), based on C. aquatica Koidz. from Kyushu. The author pointed out a resemblance to Zizania L., which is now considered to belong to the Oryzeae. Honda (1930) recognized its special position and created a subtribe Paniceae-Chikusichloeae. Keng (1931) correctly placed it in the Oryzeae, pointing out possible affinities with Zizaniopsis Doell & Aschers. and Hydrochloa Beauv. Ohwi (1942-a) recognized the subtribe, also, now in the Oryzeae, and added Hydrochloa to it; he corrected the spelling to Chikusichloinae. The two genera seem indeed distinct from the other Oryzeae by the very much reduced to absent glumes and sterile lemmas, the longstipitate fertile lemma, which is dorsoventrally flattened at anthesis, and not laterally so, and which becomes more or less terete in fruit. Otherwise the two do not resemble each other very much.