1 68 



GRAMINEAE. 



40. HOLCUS L. Sp. PI. 1047. 1753. 



Annual or perennial grasses with flat leaves and spike-like or open panicles. Spikelets 

 deciduous, 2-flowered; lower flower perfect, upper staminate. Scales 4; the 2 lower empty, 

 membranous, keeled, the first i-nerved, the second 3-nerved and often short-awned; flower- 

 ing scales chartaceous, that of the upper flower bearing a bent awn. Palet narrow, 2-keeled. 

 Stamens 3. Styles distinct. Stigmas plumose. Grain oblong, free, enclosed in the scale. 

 [Greek, taken from Pliny.] 



About 8 species, natives of the Old World. 



j. Holcus lanatus L. Velvet-grass. 

 Meadow Soft-grass. (Fig. 384.) 



Holcus lanatus L. Sp. PI. 1048. 1753. 



Softly and densely pubescent, light green, culms 

 I *4-$ tall, erect, often decumbent at the base, sim- 

 ple. Sheaths shorter than the internodes; ligule 

 y //_!// long; leaves i / -6 / long, 2 // -6 // wide; spike- 

 lets 2" long, the empty scales white-villous, the 

 upper awn-pointed; flowering scales \" long, 

 smooth, glabrous and shining, the lower sparsely 

 ciliate on the keel, somewhat obtuse, the upper 2- 

 toothed and bearing a hooked awn just below the 

 apex. 



In fields, meadows and waste places, Nova Scotia to 

 Ontario and Illinois, south to North Carolina and 

 Tennessee. Also on the Pacific Coast. Naturalized 

 from Europe. June-Aug. 



41. AIRA L. Sp. PL 63. 1753. 



Mostly annual grasses with narrow leaves and contracted or open panicles. Spikelets 

 small, 2-flowered, both flowers perfect. Scales 4; the 2 lower empty, thin-membranous, 

 acute, subequal, persistent; the flowering scales usually contiguous, hyaline, mucronate or 

 2-toothed, deciduous, bearing a delicate dorsal awn inserted below the middle; palet a little 

 shorter than the scale, hyaline, 2-nerved. Stamens 3. Stigmas plumose. Grain enclosed 

 in the scale and palet, and often adhering to them. [Greek name for Lolium temulentam.] 



Four or five species, natives of Europe. 



Panicle open; flowering scales about i" long; plants s'-io' tall. 

 Panicle contracted; flowering scales about \% long; plants 2' -4' tall. 



1. A. caryophyllea. 



2. A. praecox. 



i. Aira caryophyllea L,. Silvery Hair-grass. (Fig. 385.) 



Aira caryophyllea L. Sp. PI. 66. 1753. 



Smooth and glabrous throughout, culms s'-io 7 

 tall, erect from an annual root, simple, slender. 

 Sheaths mostly basal; ligule \%" long; leaves >'- 

 2 r long, involute-setaceous; panicle i'-\' in length, 

 open, the branches spreading or ascending, the 

 lower i' long or less; spikelets i // -i^ // long, the 

 empty scales acute; flowering scales very acute, 

 2-toothed, \" long, bearing an awn i>^ // -2 // long. 



In fields and waste places, eastern Massachusetts to 

 Virginia. Also on the Pacific coast. Local. Natural- 

 ized from Europe. Panicle silvery, shining. .May 

 July. 



