GRASSES OF SCOTLAND. 117 



longer than the calyx ; membranous at the margins, bitid at the 

 summit ; seven-ribbed^ the dorsal rib terminating in a long rough 

 awn, longer than the palea, passing behind the bifid summit. Inner 

 palea linear, lanceolate, about one-third shorter than the outer palea, 

 with two green marginal ribs, delicately fringed. 



Obs. — Some varieties of this grass, especially those found in dry 

 exposed situations, and somewhat stunted in their growth, very much 

 resemble Bromus diandrus in their general appearance, and which 

 can be only satisfactorily determined by the examination of the ribs 

 of the outer palea. In Bromus sterilis the outer palea has seven dis- 

 tinct ribs placed at equal distances ; — whereas in Bromus diandrus 

 the outer palea has also seven ribs, but the rib on each side of the dorsal 

 rib is indistinctly seen, and the two marginal ribs on each side are 

 prominent and placed close together. (See Fig. -1.) 



Bromus sterilis is distinguished from Bromus asper, in the outer 

 palea not being hairy, and the awn being longer than the palea ; — 

 whereas in B. asper the outer palea is hairy, and the aim is never the 

 length of the palea. (Plate LL) 



This grass grows in shady places, on rather dry sandy soil, espe- 

 cially imder hedges and road-sides. It is applied to no agricultural 

 use, as cattle seldom or ever eat it, owing probably to the long rough 

 awns with which the spikelets are furnished. It is a common grass 

 throughout Scotland, England, and Ireland; also a native of Lap- 

 land, Norway, Sweden, Germany, France, Italy, and North Africa. 

 Not found in America. Its limit of altitude seems to be about 600 

 feet above the sea. 



Flowers in the third week of June, and ripens its seed in the last 

 week of July. 



78. Bromus diandrus. * 

 Upright Anriual Brome-Grass. 



Specific Characters. — Large glume three -ribbed. Awn equal in 

 length to the palea. Panicle erect. (Plate L.) 



Description. — It grows from six to twelve inches high. The root 

 is annual, fibrous. Stem erect, smooth, round and polished ; beai'ing 



* Bromus diandnts, Curtis, Smith, Hooker. Bmnus madtitcnsls, Linn. Koch. 



