POACEAE 129 
an s with erect pyramidal panieles, maniar several-flowered spikelets, 
3 mm. long, on curved pedicels; also Va., Ark., Cal, Ore.—Nat. Eu. 
90. DACTYLIS L. An erect perennial with flat blades. Spikelets few- 
flowered, compressed, finally disarticulating above the glumes and between the 
florets, ni sessile in dense l-sided fasci- 
hese borne at the en the few 
panicle- -branehes: glumes aie ae carinate, 
acute, hispid-ciliate on the keel; lemmas com- 
pressed-keeled, mucronate, 5- Were. eiliate 
on the keel.—T wo species, native of Eurasia. 
1. D. glomerata L. Stems in large often 
ri tufts, ad em. tall: leaf- ee 
rous: pan 8-15 em. long, fe 
sim pipe prs spreading in anthesis 
ect in fruit.—(ORCHARD-GRAS aste- 
pikes olds and orchards, ranging from the 
Piedm of Ala. northward ae the 
cooler a of the U. $8. f Eu. 
91. POA L. Annuals or usually perennials, low or rather tall, with spike- 
lets in open or contracted panicles, the narrow linear blades ending in a navicular 
point. Spikelets 2- several-flowered, the rachilla disarticulating above the glumes 
and between the florets, the uppermost floret reduced or rudimentary; glumes 
acute, keeled, somewhat unequal, the first 1-nerved, the second usually 3-nerved: 
lemmas somewhat keeled, acute or acutish, piss s, membranaceous, e some- 
what searious at the tip, 5-nerved, the nerves somewhat pubescent.— Two 
hundred species, in cool and a eae regions generally. os -GRASSES. 
PEAR-GRASSES. 
Plant annual, low, usually less than 25 cm. tall. I. ANNUAE. 
Plan nt perennial, taller 
Creeping POELO pr resent. II. PRATENSES. 
Creeping rootstock wanting. III. TRIVIALES. 
I. AN 
Florets with cottony hairs at base: ‘lemmas inane 3-nerved, 
the intermediate nerves obscure. 1. P. Chapmaniana. 
Florets not cottony at base: lemmas 5-nerved, the inter- 
mediate nerves distinct. 2. P. annua. 
II. PRATENSES 
Stem distinctly ges wiry: plant blue green. . P. compressa. 
Stem terete or nearl 
Plant dioecious: es icle silvery. . P. arachnifera. 
Plant is perfect “spikelets panicle not silvery. 
Lea about as long as the stem ; panicle few diowered, 
ender Tae spikelet-bearing near the ends. . P. cuspidata. 
E Shorter than the m ms: panicles pyramidal, 
the spikelets rather erow . P. pratensis. 
III. TRIVIALES 
Leaf-sheaths scabrous: panicle pale. . P. trivialis. 
Leaf- oe smooth. 
Lem n cottony at the base, pubescent below between 
the uo es. . P. autumnalis. 
Lemmas PUN 
Panicle-branches spikelet bearing from about the middle. . P. sylvestris. 
Panicle-branches bearing a few spikelets near the ends. 
Marginal nerves glabrous. . P. alsodes. 
Marginal nerves pubescent. . P. Wolfii. 
