112 Chase — Notes on Genera of Panicetz. IV. 



Cameron, 15 (coll. of 1899)," is included in the genus. The type has not 

 been examined but the description and plate identify the species with the 

 following. 



Stereochlaena Hack. Proc. Rhodesia Sci. Assoc. 7 : ' l 65. 1908. One 

 species, S. Jeffreyssii Hack., " Bulawayo, Maio, 1907, leg. Jeffreys, no. 

 46,83." Professor Hackel kindly sent spikelets of the type for deposit 

 in the National Herbarium, and stated in a letter that Stereochlaena " is 

 identical with Chloridion Stapf, Hook. Ic. 2040 (1900)." 



In this genus the fruit is cartilaginous-indurated, brown, papillose, the 

 margins of the lemma white and hyaline, as in the other genera of this 

 group. The inflorescence consists of few to several slender racemes, digitate 

 at the summit of the culm; the short-pediceled, lanceolate, spikelets are 

 in pairs, the first glume is wanting, the second a minute scale; the sterile 

 lemma is attenuate into a slender scabrous awn, 4 or 5 times longer than 

 the body of the spikelet, and encloses a minute cleft palea. Stapf says 

 " Chloridion might be described as a Digitaria in which the lower glume 

 is entirely suppressed and the upper reduced to a scale, whilst the lower 

 (barren) valve runs out into a fine bristle-like awn." 



7. Genus ACRITOCHAETE Pilger. 



Acritochaete Pilger in Engler, Bot. Jahrb. 32 : 53. 1902. The genus is 

 based on one species, A . Volkensii Pilger ( op. cit. 54) " Ost-Afrika, am Kili- 

 mandscharOj im Griitelwald oberhalb Marangu verbreitet, 2100 m. s. m. 

 ( Volkens n. 1278. ) " A portion of a raceme from the type specimen was 

 kindly sent to the National Herbarium by Dr. Pilger. 



This genus like the preceding is very unlike any known American grass. 

 In Acritochaete the scarcely indurated fruit is more like that of Reimaro- 

 chloa or Hymenachne than like that of the preceding genera in texture, 

 but the broad, white, thin-membranaceous margins of the lemma are like 

 those found in this group. Chloridion is evidently related to Synthei'tsma, 

 and Acritochaete is more nearly related to Chloridion than to any other 

 known genus. The inflorescence consists of a few slender erect, distant 

 racemes; the solitary, short-pediceled, lanceolate spikelets in two rows 

 on one side of the slender raceme ; the first glume is reduced to an obscure 

 scale, the second glume and sterile lemma are attenuate into long, slender, 

 more or less twisted and irregularly flexuous awns several times longer 

 than the body of the spikelet, the awns of the several spikelets more or less 

 entangled. 



8. Genus THRASYA H. B. K. 



Thrasya H. B. K. Nov. Gen. & Sp. 1 : 120. pi. 39. 1816. This is based 

 on a single species, T. paspaloides (op. cit. p. 121). " Crescit in calidis, 

 subinundatis insulae Orinocensis Panumana, inter vicos Atures et San 

 Borja." The type has not been examined nor has any specimen of this 

 species. The generic characters here given are based upon a study of 

 specimens of Panicum thrasyoides Trin. (Thrasya hirsuta Nees) and P. 



