404 MONOCOTYLEDONOUS PLANTS. 



28. HOLCUS. Linn. 



Glumes 2-valved, 2-flowered, nearly equal. Palea 2. Flo- 

 rets dissimilar, polygamous, one awned, the other awnless, 

 without any imperfect one between them. Panicles contract- 

 ed. Triandria. Digynia. 



H. lanatus Linn. : perfect floret inferior and awnless ; sterile one 

 with a curved awn included in the glume ; root fibrous. 



HAB. Wet meadows. N. S. W. to Mich. July. If. Culm 

 18 inches high. Panicle oblong, contracted, whitish. 



Soft Grass. 



29. HIEROCHLOA. Gmel. 



Glumes 2-valved, 3-flowered, scarious. Lateral florets an- 

 theriferous, triandrous. Central floret perfect, diandrous, (rare- 

 ly triandrous.) Panicle contracted, ovate. 



Triandria. Digynia. 



1. H. bortalis R. $ & * panicle subsecund, a little spreading ; pe- 

 duncles smooth ; florets unarmed ; lower palea ciliate on the margin ; 

 root creeping. Holcus odoratus Linn. Mich. H.fragrans Pursh. 



HAB. Wet meadows. Can. to Vir. N. to Subarc. Amer. May. 

 If. Culm 18 inches high. Panicle few-flowered, pyramidal, 

 purple and brown. Sweet-scented. 



2. H. alpina R. 4* & * panicle ovate, contracted ; spikelets com- 

 pressed, longer than the branches ; glumes lanceolate, almost nerve- 

 less ; lateral florets triandrous ; one of them with an awn about as 

 long as the valves ; sides almost smooth ; margin ciliate. 



HAB. Summit of White Hills, N. H. Big. N. to Arc. Amer. 

 ^ June. If. Culm 68 inches high. FUncerg larger than in the 

 preceding, purple. 



30. URALEPSIS. Nutt. 



Glumes 2 3-flowered, much shorter than the florets, which 

 are stipitate and distinct, Palea: 2, very unequal, distinctly 

 villous on the margins ; the lower one tricuspidate ; the cen- 

 tral cusp produced into a short bristle ; upper palea concave 

 on the back and incurved. Seed gibbous, coated. Panicle 

 simple, racemose. Triandria. Digynia. 



U. aristulata Nutt. : lateral panicles concealed in the sheaths of the 

 leaves; terminal ones partly exsert ; glume 3-flowered ; bristle of the 

 palea as long as the lateral cusps. 



HAB. Sea coast and sandy fields. N. Y. and Penn. Aug. . 

 Culms cespitose, procumbent at base. Flowers axillary and 

 terminal, purple. 



