MACLOSKIE: GRAMINE/E. 157 



g2. Stigmas long, feathery, protruding, rarely remaining enclosed. 



//. Fruit stripped of the floral glume and palea ; mostly with splitting, 



loosely attached pericarp. 20. Sporobolus, p. 180. 



hz. Fruit enclosed in the floral glume and palea, with adhering pericarp. 

 i. Spikelet at length falling away as a whole, often leaving the 

 stump of its jointed pedicel. Empty glumes 2, awned ; floral 

 glume smaller, with a short awn. 2 1 . Polypogon, p. 1 8 1 . 

 12. Spikelet leaving the empty glume persisting on the unsegmented 



hairy pedicel. Panicle mostly lax. 



j. Empty glumes exceeding the usually awned floral glume. 

 No prolongation of the rachilla above the palea. Callus 

 bare. 22. Agrostis, p. 182. 



J2. Rachilla or callus with a hairy tuft prolonged above the palea. 

 Floral glume dorsally awned, hairy. Spikelets all herma- 

 phrodite. 23. Calamagrostis, p. 192. 

 D2. Spikelets 2 many-flowered. 



e. Floral glume usually shorter than the empty glumes. Awn dorsal, bent, rarely 

 apical or none, and then with 2 opposite flowers and the rachilla not prolonged. 



(AVENE.E.) 



f. Spikelets easily deciduous as a whole, 2 -flowered, upper flower staminate, 



with a recurved awn. 24. Holcus, p. 196. 



f2. Fruiting spikelets separating from the persisting empty glumes. 

 g. Spikelets always 2-flowered, without prolongation of the axis. 



//. Empty glumes coriaceous, broad, many-nerved. Floral glumes 



long-ciliated. Paleae naked. 25. Eriachne, p. 197. 



h2. Both floral glumes and paleae naked. Flowers close together, equal, 



perfect. Panicle lax. 

 i. Empty glume semicircular, and spikelet globular, awnless. 



26. Airopsis, p. 197. 



12. Empty glumes thin, acute. Flower glumes awned, 2-toothed. 



27. Aira, p. 197. 



g2. Spikelets 2-several-flowered, with the axis prolonged above the second 



flower. 



//. Floral glumes toothed and dorsally awned. Upper flower some- 

 times sterile. Inflorescence not a true spike. 

 i. Fruit free, not grooved. Spikelets small, not I cm. long. 

 j. Floral glume finely erose-dentate or 2-lobed. 



28. Deschampsia, p. 199. 

 j2. Floral glume cleft or 2-toothed, or the teeth awned, besides 



the dorsal awn. 29. Trisetum, p. 203. 



*2. Fruit grooved, mostly adhering to the palea. Paniculate. 

 Spikelet exceeding i cm. long. Grain apically hairy. 



30. Avena, p. 206. 



h.2. Awn generally twisted and arising between the lobes (often awned) 

 or teeth of the floral glume. Spikelets 3-many-flowered, upper- 

 most flower sometimes imperfect 31. Danthonia, p. 207. 



