GRAMINEAE (GRASS FAMILY) 



147 



long ; spikelets 5-7 min. long ; first glume warty-tuberculate on the nerves ; 

 florets stiffly ciliate on the margins. (C. americanum Spreng.) Wet pine 

 barrens, Va., and southw. Taste very pungent. FIG. 140. 



56. DACTYLOCTENIUM Willd. CROWFOOT GRASS 



Spikelets several-flowered, the uppermost imperfect, sessile and crowded in 

 2 rows along one side of a continuous rhachis, which extends beyond the spike- 

 lets in a naked point ; glumes broad, keeled ; lemmas boat- 

 shaped, cuspidate ; palea equaling the lemma, acute, deeply 

 folded between the ciliate-winged keels ; grain reddish brown, 

 the loose pericarp transversely wrinkled. Annual, with more 

 or less decumbent and creeping base, and 2-6 stout unilateral 



spikes digitate at the apex of the culm. (Name from 



finger, and Kreviov, a little comb, alluding to the digitate and 



pectinate spikes.; 



1. D. AEGYPTIUM (L.) Richter. Usually glabrous ; culms 

 rooting at the lower nodes; spikes 1.5-5 cm. long; glumes 

 scabrous on the keel, the second cuspidate ; the awned tip 

 of lower lemma inflexed, that of the others straight or 

 curved. (D. aegyptiacum Willd. ; Eleusine aegyptia Pers.) 

 Yards and cultivated fields, N. Y., 111., and southw. (Nat. 

 from tropics of the Old World.) FIG. 141. 



141. D. aegyptium. 

 Inflorescence x %. 

 Spikelet x 2. 

 Fruit x 3. Seed x 4. 



142. E. indica. 

 Part of inflorescence x 

 Spikelet and floret x 2. 

 Fruit and seed x 4. 





57. ELEUSINE Gaertn. GOOSE GRASS. YARD GRASS 



Spikelets several-flowered, awnless, florets perfect or uppermost staminate, 



sessile and closely imbricated in 2 rows along one side of a continuous rhachis, 

 which does not extend beyond the terminal spikelet ; 

 glumes unequal, shorter than the floret, scabrous on the 

 keels ; lemmas broader, with a thickened 5-ribbed keel ; 

 palea shorter, acute, the narrowly winged keels distant ; 

 grain black, the loose pericarp marked with comb-like 

 lines, free within the subrigid lemma and palea. Coarse 

 tufted annuals with stout unilateral spikes digitate or 

 approximate at the apex of the culms. (Name from 

 'EXeuo-^i/, the town where Ceres, the goddess of harvests, 

 was worshiped.) 



1. E. fNDicA Gaertn. Glabrous ; culms flattened, de- 

 cumbent at base ; sheaths loose, overlapping, compressed ; 



spikes 2-10, 2.5-8 cm. long ; spikelets appressed, 3-5-flowered, about 5 mm. long. 



Yards and waste ground, Mass., n. 111., Kan., and southw. (Nat. from tropics 



of the Old World.) FIG. 142. 



58. LEPT6CHLOA Beauv. 



Spikelets 2-several-flowered, the uppermost floret usually 

 imperfect or rudimentary, sessile or nearly so, in 2 rows 

 along one side of the slender continuous rhachis ; glumes and 

 lemmas keeled, the latter 3-nerved, acute, awnless or short- 

 awned, exceeding the palea. Usually tall annuals with flat 

 leaves and elongated simple panicles composed of the numer- 

 ous very slender spikes scattered along the main axis. 

 (Name composed of Xe-rrrbs, slender, and x^ a grass, from 

 the long attenuated spikes.) 



1. L. filif6rmis (Lam.) Beauv. Culms 4-12 dm. high ; 

 shi'Mhs papillose-hairy ; spikes 20-40, 5-10 cm. long, ascend- 

 ing; spikelets about 3 mm. long; glumes more or less 

 mucronate, nearly equaling the 3-4 awnless florets. (L. 

 mucronata Kunth ; L. att'enuata Steud.) Fields, Va. to 

 1, Mo., and southw. Aug. FIG. 143. 



143. L. filiformis. 

 Inflorescence x Vio- 

 A part of same with 



2 spikelets x iy 2 . 

 Spikelet and floret x 3. 



