160 POACEAE 
1. Blymus striatus Willd. Stems 3-9 dm. tall: leaf-sheaths glabrous or hirsute ; 
blades 1-2.5 dm. long, 4-10 mm. wide, pubescent above: spike 6-12 cm. long, often nod- 
ding, slender : spikelets 1-3-flowered, the empty scales 2-2.5 em. long, including the slen- 
der rough awn, 1-3-nerved, the nerves, and often the whole scale, rough, hispid or hirsute, 
the flowering scales about 6 mm. long, hispid or hispidulous, each bearing a slender awn 
1.5-3 cm. long. 
In woods and on banks, Maine and Ontario to Tennessee, Nebraska and Kansas. Summer. 
2. Elymus Virgínicus L. Stems 6-9 dm. tall: leaf-sheaths sometimes pubescent, 
the uppermost usually inflated and enclosing the base of the spike: blades 1-3.5 dm. long, 
4-16 mm. wide, rough: spike 5-18 cm. long, broad, stout, upright ; spikelets 2-3-flowered, 
the empty scales very thick and rigid, lanceolate, 1.5-2.5 cm. long, including the short 
awn, 5-7-nerved, the flowering scales 6-8 mm. long, each bearing a rough awn 4-18 mm. 
long, or rarely awnless. 
In moist soil, especially along streams, Nova Scotia and New Brunswick to Manitoba, Florida and 
Texas. Summer. 
3. Elymus hirsutiglümis Scribn. & Sm. Stems 3-9 dm. tall, erect: leaf-sheaths 
longer than the internodes, the uppermost often inflated and enclosing the base of the spike ; 
blades 2-3 dm. long, 8-18 mm. wide, very rough on both surfaces: spike 6-15 cm. long, 
stout, the rachis pubescent: spikelets crowded in pairs, 2-5-flowered, the empty scales 
linear, 10-12 mm. long, thick, 3-5-nerved, the nerves hirsute, each acuminate into an awn 
as long as or shorter than the body of the scale, the flowering scales lanceolate, 8-10 mm. 
long, each acuminate into a rough awn 12-16 mm. long. 
On river banks, Maine to North Carolina, Illinois and Nebraska, Summer. 
4. Elymus Canadénsis L. Stems 6-15 dm. tall: leaf-blades 1-3 dm. long or more, 
4-20 mm. wide, rough, sometimes glaucous: spike 1-3 dm. long, nodding, its peduncle 
usually much exserted: spikelets 3—5-flowered, the empty scales awl-shaped, rigid, 3-5- 
nerved, 16-32 mm. long, including the slender rough long awn, the flowering scales 8-14 
mm. long, nearly glabrous to hirsute and each bearing a slender rough awn 2-5 cm. long. 
On river banks, Nova Seotia and New Brunswick to Alberta, Georgia, Texas and New Mexico. 
Summer. 
5. Elymus robüstus Scribn. & Sm. Stems 9-12 dm. tall, erect, stout: leaf-blades 
firm, rough on both surfaces, 1-4 dm. long, 8-20 mm. wide: spike usually partially in- 
cluded at the base, stout, strict, 1-2.5 dm. long, compact: spikelets numerous, crowded, in 
2' s-4's, 3-4-flowered, the empty scales 10-12 mm. long, each bearing an awn about twice as 
long, the flowering scales lanceolate, 10-12 mm. long, from sparsely to densely appressed- 
pubescent, each bearing an awn 3-4.5 em. long. 
On river banks, Illinois to Arkansas, Montana and Kansas. Summer. 
120. HYSTRIX Moench. 
Usually tall grasses, with simple stems, flat leaf-blades and terminal spikes. Spikelets 
numerous, at length spreading, 2-several-flowered, usually in pairs, rarely in 3’s, sessile, 
the clusters alternate on opposite sides of the continuous rachis, the rachilla articulated 
below the flowering scales. Scales 2-several, the 21ower empty, subulate, wanting in all 
but the lowest spikelets, the flowering scales lanceolate, rigid, convolute, rounded on the 
back, the nerves confluent into the long awn ; palet somewhat shorter than the scale, 2- 
keeled. Stamens 3. Styles very short, distinct. Stigmas plumose. Grain oblong, ad- 
herent to the palet when dry. : 
1. Hystrix Hystrix (L.) Millsp. Stems 6-12 dm. tall: leaf-blades 1-2.5 dm. long, 
6-12 mm. wide, rough above : spike 7-18 cm. long: spikelets at length widely spreading, 
8-12 mm. long, exclusive of the awn, readily deciduous, the empty scales present only some- 
times in the lowest spikelets, the flowering scales 8-12 mm. long, each acuminate into an 
awn about 2.5 em. long. [Asprella Hystrix (L.) Willd.] 
In rocky woods, New Brunswick to Ontario and Minnesota, Georgia, Illinois and Nebraska. Sum- 
mer. BOTTLE-BRUSH. 
121. ARUNDINARIA Michx. 
Tall shrubs, or rarely trees, with simple or branched stems, flat short-petioled leaf- 
blades which are articulated to the sheath, and racemose or paniculate inflorescence. 
Spikelets large, compressed, 2-many-flowered. Scales 3-many, the 2 lower empty, unequal, 
the first smaller or sometimes wanting, the flowering scales longer, membranous, many- 
nerved, at the apex obtuse, acuminate or with a short awn or mucronate ; palet scarcely 
