GENERA. xxiii 



883. TRISETUM. Glumes and outer Pale keeled, membrano-scariose, without prominent 

 nerves ; the latter ending in 2 teeth, and with a slender dorsal awn, which in most species is 

 geniculate. Seed without furrow or crest, p. 404. 



884. AVENA. Glumes herbaceous or membranous, A/rith a scariose margin. Outer Pale 

 fii-mer than glume, ribbed, ending in 2 points, with an intermediate geniculate and twisted dorsal 

 awn. Seed furrowed and crested, p. 404. 



b. Glumes decidedly falling short of the spikelet. 



896. POA. Glumes nearly equal. Outer Pale compressed, keeled, membranous, with a 

 scariose margin, entire, rather acute, unarmed. Pan. one-sided in nemoralis, compressa, and 

 annua ; equal in the others. In P. divaricata the glumes are very unequal, p. 408. 



897. ERAGROSTIS. Glumes and outer Pale similar, membrano-scariose throughout, 

 with 3, prominent, converging nerves, p. 410. 



898. GrLYCERIA. Glumes and outer Pale membrano-herbaceous, with sharply promi- 

 nent nerves, and a scariose margin, p. 411. 



899. SCLEROCHLOA. Glumes and outer Pale membranous, with rounded, often ob- 

 scure ribs, which disappear towards the base. Fits. cyKudrical at base, keeled in some species 

 at top, unanned, or with a minute and hardly distinguishable mucro. p. 411. 



893. CATABROSA. Glumes and outer Pale membranous at base, both eroso-truncate ; 

 the latter with 3 ribs ending in as many teeth, which are united by the scariose margin, p. 408. 



900. BRIZA. Glumes nearly equal, broad, boat-shaped, obtuse. Outer Pale boat-like, 

 heart-shaped, ventricose, keelless, unarmed, adhering to seed. p. 412. 



893. MOLINIA. Glumes 2-3-flowered, with a subulate rudiment. Pales acute, both en- 

 tire, membranous, firmer than glume, and hai'deniug on the seed. p. 408. 



901. CYKOSXTRUS. Spikelets attached to a neutral spicule or spike. Eertile Spikelets 

 1- or more flowered. Glumes scariose, keeled. Outer Pale concave, keeled, with a terminal 

 seta. Fan. one-sided, p. 412. 



902. DACTYLIS. Glumes unequal, many-flowered, acute, herbaceous, with a terminal 

 seta, compressed, and keeled. Spikelets crowded. Pan. one-sided, p. 412. 



903. PESTUCA. Glumes unequal, many-flowered, thinner than the pale. Pale ribbed, 

 rounded on the back ; very acute, or with a terminal, or very nearly terminal, seta. Pan. one- 

 sided, except in F. gigantea. p. 412. 



904. BROMTJS. Glumes unequal, many-flowered. Outer Pale ribbed, with a dorsal seta. 

 Inner with 2 ciUate ribs. Pan. equal, p. 415. 



I have given in the order Geamina a different and more natural arrangement of the genera, 

 hoping that the student who experienced difiiculties in the one, might find his account in the other. 



III. TEIGYNIA. 



247. MOK"TIA. Cal. of 2 L. Cor. of 1 petal. Caps. 1-ceUed, 3-valved, 3-seeded. (Sta. 

 3-5. Style 1. — DC.) L. opposite, somewhat succulent. Poetulacace^. p. 129. 



122. HOIiOSTEUM. Cal. 5-leaved. Pet. 5, jagged. Kl. thread-like. Caps. 1-ceUed, 

 splitting at top into 6 teeth, many-seeded. L. opposite, quite entire. Has the habit of Ceras- 

 tium. Caeyophyllace^. p. 56. 



253. POLYCARPON. Cal. 5-leaved, concave, keeled. Pet. 5, nearly entire. Pil. subu- 

 late. Caps. 3-valved, l-ceUed, many-seeded. L. opposite or in fom-s. {Styles 2, very short. 

 — DC.) Two of the three European species are pentandrous. PaeonychiK/E. p. 131. 



Tillaa. Eriocaulon. 



