TRITICUM. 



40. TRIT'ICUM Linn. Wheat-grass. 



1. T. caninum (L.) ; spike rather close, spikelets 2 /5-fl., 

 3 5-ribbed gl. and lower pales awned [upper pale emarginate , 

 axis and edges of the rachis hispid, 1. flat rough on both sides, 

 root fibrous. E. B. lo?:?. P. 62. Agropt/ron (Beauv.). St. 

 erect. Ribs on the upperside of 1. very slender. Gl. round on 

 the back, its ribs reaching the tip and joining to form the 

 short awn. Lower pale shorter than its awn; or in an alpine 

 form longer than it. Banks, rare. P. VII. E. 8. I. 



2. T. alpinum (Don) ; spike rather close, spikelets 2 6-fl., gl. usuhlly 

 shortly awned strongly 4 6-ribbed with ribs edges tip and awn asperous, 

 lower pale narrowed abruptly and with scarious margins at apex, 4- -t>- 

 ribbed with awn \ \ its length, upper pale bluntly pointed densely 

 ciliate on the lateral keels densely asperous and with a well-marked mid- 

 rib towards the apex, the two lateral ribs terminating in teeth which 



fall short of the apex, axis hairy, rachis ciliate, 1. thin flat with many 

 slender ribs, " soboliferous." Agropyron .Donianum (Buch. -White). -- 

 Variously referred to Sp. 1 and 3, but differing from both in the character 

 of the upper pale; closely allied to the Scandinavian T. violacenni 

 (Hornem.). Rocks, Ben Lawers, Mr. G.Don. Rediscovered 1878 by 

 Mr. J. C. Melvill. P. VIII. S. 



3. T. repens (L.) ; spike rather close, gl. 5 7-ribbed equalling 

 at least of the 4 5-fl. spikelet rough on the keel, lower pale 

 acuminate, axis asperous, rachis with rough angles not brittle, /. 

 mostly flat the many slender ribs each bearing a row of deciduous 

 hairs above, soboliferous. E. B. 909. P. 62. Agropyron 

 (Beauv.). L. at first involute afterwards flat, ribs on upperside 

 not much raised nor nearly hiding the in term, surface of the 

 leaf. Rachis glabrous or downy with forward prickles on the 

 angles. Gl. scarcely keeled, acuminate-subulate ; ribs reaching 

 the tip. Pales rarely awned. * [The shape of the gl. and pales varies 

 considerably, extreme forms are: var. barbatum (Duv.-Jouv.) "gl. very 

 attenuate subulate or awned, pales long-awned," and var. obtusum (Sy.) 

 " gl. obtuse obliquely truncate, pales obtuse with a minute apiculus." I - 

 Common. P. VI. Couch-grass. E. S. I. 



4. T. pun' gens (Pers.) ; spike close, gl. with 7 9 thick ribs 

 not exceeding ^ the 5 12-fl. spikelet rough on the keel, lower 

 pale acute, axis asperous, rachis nearly or quite smooth not 

 brittle, 1. with involute edges the many thick closely -placed ribs 

 slightly rough and each bearing a row of acute points above, 

 upper part of 1. wholly involute (subulate and rigid), soboli- 

 ferous. Sy. E. B. 1811. Agropyron (R. & S.) tit. erect, like 

 a corn-field. Ribs on upperside of 1. so broad and so elevated 

 as nearly to hide the interm. part of the leaf, Gl. keeled ; ribs 



