74 



PAXK'ACK.E. 



Sp. PI. 1:484 (1T9S). Trwias nicmosm Hall. Hist. Stirp. Hclv. 

 2:1413 (17G8). A Ioav, hniiiching uiimiiil, 10-30 cm. high, culms 

 smooth, 2-(5 cm. long. Lcaf-bhulcs ^-4 cm. long, flat, thin, the 

 margins clothed with prickles. Spikes 3-8 cm. long, 7-8 mm. 

 broad, with the base included in the swollen sheaths. Spikclots in 

 clusters of three, 3 mm. long, ovate-lanceolate, easil}' detached and 

 carried away by animals. 



Pa. (Phila.). >>•/•//!';/«• 3620a from Dr. Brinton; Texas, Jones; 

 Mississippi, Tntrii cult. A rare weed introiluced from Europe. 

 2. N. occidentalis (Nees). 2\ occUlcntalis Nees, Agrost. Bras. 

 28G (1829). Plant erect, 20-30 cm. high. 

 Spikes dense, 5-8 mm long, .5-0 nun. broad, 

 the base often included. S|)ikelets in clusters 

 of two. ovoid. 2-2.5 mm. long. The [)edicels 

 with a broad calloused base. 



Arizona, Priin/Ic in 18S4; Mexico, Pn"«^?e 



Fio. 18. - X<m., ««-*^l; Colorado, Jones. 



Spikelet. ]'.). (72). ScHAFFNERA Benth., Journ. 

 Linn. 8oc. 19: 03 (1881) 



Spikelets 1-4, 1-flowered, jointed on very short axillary pe- 

 duncles, flowers perfect or sterile, fllumes 2-;5; if 3, then the first 

 is ciliate-f ringed, 3-ner;ed, and about 1 mm. long, second almost 

 hyaline, 2-3 mm. long, 3-5 awned, third as long as the spikelet, 

 several-nerved, with an awn back of the apex; palea hyaline. 2- 

 nerved, 2-tootlied or obtuse. Stamens 3. Anthers long and narrow. 

 Styles 2, distinct, long and slender. 



The above differs in some respects from the description in Oex- 

 ERA Plantaui'M, but corresponds to the specimen as T observed 

 it. IJelitham at one time united this with tlie genus Zoi/siu 

 "Willd. At first sight it seems to resemble Cafhesterlium. It a[)- 

 proaches sonu^ species of Aiu/ro/m/on {f'i/tiif)o/)o(/on) and of Aphidit. 



One species is known, and that is found in Mexico. 



1. S. gracilis Benth. hook. Ic. PI. (XIV.) 5!». /. 1378 (1882). 

 A low, diffuse, branching annual. 15cm. high. Sheaths 1 cm. or 

 less in length; blades rough, narrow, 2-;j cm. long. Pecluncjts 

 unequal, partially included in the sheaths. Part of the spikelets of 



ciili'ntiilix. 

 (Kicliarilson.) 



