﻿GRASSES OF SCOTLAND. 31 



18. HORDEUM PRATENSE. * 



Meadow Barky. 



Specific Characters. — All the glumes bristle-shaped. (Plate XL) 



Description. — It grows from eighteen inches to two feet or more 

 liigh. The root is perennial, fibrous, (" becoming bulbous in bar- 

 ren ground, occasionally overflowed," Smith.) Stem round, smooth, 

 erect, and glossy ; bearing four or five leaves with smooth striated 

 sheaths ; the upper sheath longer than its leaf, crowned with a very 

 short ligule. Joints smooth. Leaves linear, flat, acute, roughish, 

 and somewhat hairy on both surfaces, the edges minutely serrated. 

 Inflorescence spiked. Spike about an inch and a-half in length, dense 

 and uniform ; the rachis jointed, very brittle, toothed alternately on 

 each side, the intermediate spaces flattened and bordered. Spikelets 

 arranged in threes on each tooth of the rachis ; of one-awned floret. 

 Calyx of the central spikelet of two bristle-shaped glumes (Fig 1 ) 

 of equal length. Central floret of two palese, the outer palea three-rib- 

 ed, terminating in a long, rough awn, rather longer than the palea ; 

 inner palea acute, with a delicate bristle at the base, about half the 

 length of the palea. Lateral spikelets pedunculated, the glumes bris- 

 tle-shaped, (Figs. 2 and 3), rough. Lateral floret imperfect, furnish- 

 ed with a short awn, not as long as the palea ; occasionally the awn 

 is altogether wanting. 



Obs. — Hordeum pratense is distinguished from Hordeum murinum 

 in being of a taller and more slender habit, with the awns of the spike- 

 lets shorter ; the glumes of the middle spikelet bristle-shaped, and 

 not fringed ; florets of the lateral spikelets with very short awns ; — 

 whereas in H. murinum the glumes of the middle spikelet are dilated 

 and fringed, and the florets of the lateral spikelets with very long 

 awns. (Fig. 4.) 



From Hordeum maritimum, in being of a taller and more slender 

 habit ; all the flumes bristle-shaped (Fig. 2.) ; — whereas in H. mari- 

 timum the inner glume of the lateral spikelet is dilated on one side, 

 in the form of half-ovate. (Fig. 2.) 



Although this grass produces a tolerable early spring crop of foli- 



* 



* Hordeum pratense, Smith, Hooker, Lindley. Hordeum nodosum, Koch. 



