AXILLARY CLEISTOGENES IN SOME AMERICAN 
GRASSES 
Agnes Chase 
A few years ago a previously unknown form of cleistogene was dis- 
covered in autumnal specimens of Triplasis purpurea^ These were 
solitary, sessile, single florets without glumes, and were borne in the 
lower sheaths, clasped in the wings of an indurate prophyllum (fig. i). 
It was noted that specimens bearing these cleistogenes readily dis- 
jointed at the nodes. With this character and a slight swelling above 
the nodes as clues, other examples were sought from time to time with 
the result that some twenty more grasses were found to p'roduce similar 
cleistogenes. They are produced by all the species native in the 
Fig. I. Triplasis purpurea. Ordinary Fig. 2. Danthonia spicata. Ordinary 
spikelet (chasmogene) and cleistogene spikelet and cleistogene, with subtending 
and grain of each — X 5. prophyllum, and grain of each — X 5- 
United States of three genera, Triplasis with three species, Danthonia 
with twelve, and Cottea with one. They are also found in Muhlen- 
bergia microsperma and in Pappophorum Wrightii. In all cases the 
cleistogenes, borne at the lower nodes of flowering culms and not in 
leafy shoots, are strikingly different from the chasmogenes (that is, 
iSee Bot. Gaz. 45: 135-136. 1908. 
254 
§ 
