152 POACEAE 
many-flowered, ovate to oval when mature, 12-25 mm. long, the flowering scales 8-10 mm. 
long and hispidulous on the keel. 
In sands along the seacoast, Virginia to Florida and Texas. Alsoin the West Indies and South 
America. Fall. SEA Oats. 
109. DISTICHLIS Raf. 
Perennial dioecious grasses, with rigid creeping or decumbent stems concealed by the 
overlapping leaf-sheaths, stiff flat or convolute leaf-blades, and contracted panicles. 
Spikelets many-flowered, unisexual, more numerous in the staminate than in the pistillate 
panicles, the rachilla continuous in the staminate, articulated in the pistillate spikelets. 
Seales many, acute, keeled, the 2 lower empty, narrow, the flowering scales longer and 
broader, firm-membranous or nearly coriaceous; palet compressed, 2-keeled, the keels 
sometimes narrowly winged. Stamens 3. Styles thickened at the contiguous but distinct 
bases, moderately long. Stigmas plumose. 
1l. Distichlis spicàta (L.) Greene. Stems 1-6 dm. long, erect, or often decumbent 
at the base, from a long rootstock: leaf-sheaths overlapping and often crowded ; blades 
1-15 em. long, 2-4 mm. wide, flat or involute: panicle dense and spike-like, 2-6 cm. long, 
its branches erect : spikelets 8-18 mm. long, 6-16-flowered, pale green, the flowering scales 
3-5 mm. long, acute or acuminate.  [ D. maritima Raf. ] 
On salt meadows along the Atlantic coast from Maine to Florida and Texas, on the Pacifie Coast, 
and in saline soil throughout the interior. Summer. SPIKE GRASS. 
110. DACTYLIS L. 
Perennial usually tall grasses, with flat leaf-blades and open or contracted panicles. 
Spikelets in head-like clusters which are unilaterally arranged and crowded at the ends of 
the branches, 3-5-flowered, the flowers perfect or the upper ones staminate. Scales 5-7, 
keeled, the 2 lower empty, unequal, mucronate, the second the larger, the flowering scales 
larger, more rigid, the keel ciliate and excurrent as a mucro or short awn; palet nearly . 
as long as the scale, 2-keeled. Stamens 3. Styles distinct. Stigmas plumose. 
1. Dactylis glomerata L. Stems 6-12 dm. tall, tufted, erect: leaf-sheaths smooth 
or rough ; blades 7-23 cm. long, 2-6 mm. wide, flat, rough : panicle 7-20 cm. long, its 
branches spreading or ascending in flower, erect in fruit: spikelets in dense capitate clusters, 
MTM E the flowering scales 4-6 mm. long, rough, pointed or short-awned, ciliate on 
the keel. : 
In fields, meadows and waste places, New Brunswick to Manitoba, Georgia and Colorado. Natu- 
ralized from Europe. Summer. ORCHARD GRASS. 
111. POA L. 
Annual or perennial grasses, rarely dioecious, with flat leaf-blades and open sometimes 
contracted panicles, the branches often drooping. Spikelets 2-6-flowered, the flowers per- 
fect, or rarely unisexual, the glabrous or rarely somewhat pilose rachilla articulated between 
the flowers. Scales 4-8, membranous, keeled, acute or obtuse, awnless, the 2 lower empty, 
persistent, the flowering scales usually longer, frequently pubescent on the callus and the 
midnerve and marginal nerves, the hairs often long and curled; palet shorter than the 
scale, 2-nerved or 2-keeled. Stamens 3. Styles short, distinct. Stigmas plumose. MEADOW 
Grass. SPEAR GRASS. BLUE GRass. 
Annuals or biennials : stems densely tufted, low, usually less than 3 dm. long. 
Flowering scales distinctly 5-nerved, not webby at the base. 1. P. annua. 
Flowering scales 3-nerved or sometimes with a pair of obscure additional ; 
nerves, webby at the base. 2. P. Chapmaniana. 
Perennials: stems usually exceeding 3 dm. in height. 
A. Plants green, with no long rootstocks. 
a. Flowering scales with long crimped hairs at the base. 
Flowering scales with only the midnerve pubescent. 
Flowering scales 2.5 mm. long, the midnerve sparsely pubescent: plant 
yeliowish green. 
Flowering scales 3.5 mm. long, the midnerve densely pubescent: plant 
green. 4. P. alsodes. 
Flowering scales with the midnerve and lateral nerves pubescent. 
* Panicle open, its branches spreading: spikelets not crowded. 
Midnerve of the flowering scale pubescent only below the middle. 
Flowering scales about 3mm. long: basal leaves usually rela- i 
tively short. 5. P. pratensis. 
Flowering scales 4-5 mm. long: basal leaves very long, often : 
equalling the stem in length or nearly as long. 6. P. brevifolia. 
. P. trivialis. 
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