GRAMINE^E. (GRASS FAMILY.) 551 



divaricate, the lateral a little shorter than the middle one. Virginia to Illinois, 

 and soutlnvestward. Resembles small forms of the next. 



# * Aims united below into one, jointed with the apex ofthepalea: root annual. 



7. A. tuberculosa, Nutt. Culm branched below (6' -18' high), tumid 

 at the joints ; panicles rigid, loose ; the branches in pairs, one of them short and 

 about 2-flowered, the other elongated and several-flowered; glumes (!' long, in- 

 cluding their slender-awned tips) longer than the palea; which is tipped with 

 the common stalk (about its own length) of the 3 equal divergently-bent awns 

 (l'-2' long) twisting together at the base. Sandy soil, E. Massachusetts to 

 New Jersey ; also Wisconsin, Illinois, and southward. 



16. SPAR TIN A, Schreber. COED or MABSH GBASS. 



Spikelets 1 -flowered, without a rudiment, very much flattened laterally, spiked 

 in 2 ranks on the outer side of a triangular rhachis. Glumes strongly com- 

 pressed-keeled, acute, or bristle-pointed, mostly rough-bristly on the keel ; the 

 upper one much larger and exceeding the pointless and awnless palese, of which 

 the upper is longest. Squamulae none. Stamens 3. Styles long, more or less 

 united. Perennials, with simple and rigid reed-like culms, from extensively 

 creeping scaly rootstaicks, racemed spikes, very smooth sheaths, and long and 

 tough leaves (whence the name, from ariraprivr), a cord, such as was made from 

 the bark of the Spartium, or Broom). 



# Spikelets compactly imbricated, rough-hispid on the keels : spikes more or less pedun- 

 cled: culm and leaves rigid. 



1. S. cynosnroides, Willd. (FRESH-WATER CORD-GRASS.) Culm 

 rather slender (2 -4 high) ; leaves narrow (2 -4 long, ' or less wide below), 

 tapering to a very slender point, keeled, flat, but quickly involute in drying, 

 smooth except the margins ; spikes 5-14, scattered, spreading ; rhachis rough oa 

 the margins ; glumes awn-pointed, especially the upper, the lower equalling the lower 

 palea, whose strong rough-hispid midrib abruptly terminates below the membra- 

 nous apex. (Trachynotia cynosuroides, Michx. Limnetis, Pers.) Banks of 

 rivera and lakes through the interior, chiefly northward. Aug. Spikes 2' -3' 

 long, straw-color. Glumes strongly serrulate-hispid on the keel ; the awn of the 

 upper one about $ long. Palese somewhat unequal. Certainly distinct from 

 the next, to which, in strictness, the Linnsean name belongs. 



2. S. polystacliya, Willd., Muhl. (SALT KEED-GRASS.) Culm tatt 

 and stout (4 - 9 high, often 1' in diameter near the base) ; leaves broad (%' to 1'), 

 roughish underneath, as well as the margins ; spikes 20-50, forming a dense oblong 

 raceme (purplish) ; glumes barely mucronate, the lower half the length of the equal 

 palece, of which the rough-hispid midrib of the lower one reaches to the apex. 

 (Trachynotia polystachya, Michx. Dactylis cynosuroides, L. ! in part, excl. 

 var .) Salt or brackish marshes, within tide-water, especially southward. 



3. S. juncea, Willd. (RUSH SALT-GRASS.) Culms low (l-2 high) 

 and slender ; leaves narrow and rush-like, strongly involute, very smooth ; spikes 1-5, 

 on very short peduncles ; the rhachis smooth ; glumes acute, the lower scarcely | 

 the length of the upper, not half the length of the lower palea. (Dactylis pa- 



