GRASS FAMILY 



203 



14. Poa rhizomata Hitchc. 



466. 



Timber Bluegrass 



Fig. 



1912. 



Poa rhizomata Hitchc. in Jepson, Fl. Calif. 1: 155. 



Perennic'il, fnjm creeping rhizomes ; culms erect, 30- 

 60 cm. tall, smooth; sheaths smooth, the lower loose 

 and papery ; ligule 2-3 mm. long f blades flat or folded, 

 1-2 mm. wide, 3-7 cm. long, the culm blades about 2, the 

 upper erect, about 2 cm. long ; panicle long-exserted, ob- 

 long, contracted, 2-5 cm. long, the branches short, slen- 

 der, mostly in twos, ascending, few-tlowered ; spikele.ts 

 about 6 mm. long, 3-5-flowered ; glumes unequal, rather 

 broad, acute, scabrous on the keels, the first 1-nerved, 3 

 mm. long, the second 3-nerved. 4 mm. long; lemmas 5 

 mm. long, acutish, copiously webbed at base, short- 

 pilose on keel below, and sparingly so on lower part of 

 marginal nerves, the intermediate nerves faint, sparingly 

 scabrous between the nerves: palea ciliate on the keels. 



Damp, shadv woods, in tlie Transition Zone; Oregon, northern Ca 

 Apr.-June. Type locality: Oro Fine, Cailfornia. 



ifornia (Siskiyou County), and Idali'). 



15. Poa trivialis L. 

 Rouffh-stalked Meadow Grass. 



Fig. 467. 



Poa trivialis L. Sp. PI. 67. 1753. 



Perennial, without rhizomes, culms erect from a de- 

 cum.bent base, often rather lax, scabrous below the 

 panicle, 30-100 cm. tall; sheaths retrorsely scaberu- 

 lous ; ligule 4-6 mm. long ; blades flat, scabrous, 7-15 

 cm. long, 2-4 mm. wide ; panicle oblong, 6-15 cm. long, 

 the lower branches about 5 in a whorl; spikelets usu- 

 ally 2-3-flowered, about 3 mm. long; lemma 2.5-3 min. 

 long, glabrous except the slightly pubescent keel, the 

 web at base conspicuous, the nerves prominent. 



Moist places, through the northern United States; introduced 

 from Europe; on the west coast from Alaska to Humboldt 

 County, California {Tracy). May-June. Type locality, European. 



16. Poa leptocoma Trin. 

 Bog Bluegrass. Fig. 468. 



Poa Icttocuiua Trin. Mem. Acad. St. Petersb. VI. Math. Phys. 



Nat. 1: 374. 1830. 

 Poa lu.viflora Buckl. Proc. Acad. Phila. 1862: 96. 1863. 

 Poa paucispicnla Scribn. & Merr. Contr. U. S. Nat. Herb. 13: 



69. pi. 15. 1910. 



Perennial, without rhizomes, culms loosely tufted, 

 erect from a slightly decumbent base, smooth, rather 

 lax, 10-50 cm. tall; sheaths smooth or slightly scaberu- 

 lous ; blades flat, lax, scabrous, 1-3 mm. wide ; panicle 

 loose and open, 5-10 cm. long, the slender branches 

 naked below, spreading, or the lower finally reflexed, 

 mostly in twos ; spikelets mostly 2-3-flowered ; lemmas 

 about 3 mm. long, villous on the keel and less so on 

 the lateral nerves, the web at base inconspicuous, the 

 intermediate nerves indistinct. 



Damp, often shady places, boggy or springy soil, in the Hud- 

 sonian Zone; Alaska to California (Mount Dana). July-Aug. 

 Type locality: Sitka. 



