m ARACEAE. 



Scirpus atrovirens Muhl. Similar to S. microcarpus; stems taller, often 

 \m 150 cm high; panicle much denser; spikelets dark greenish-brown, ovoid 

 vlindric. 3-8 mm. long, in heads of 10-30; scales acuminate; akene oblong- 

 . fa, sharply pointed. Waitsburg, Horner. 



69. HEMICARPHA. 



Mostly annual, low tufted plants; stems and leaves erect or 

 spreading, almost filiform; spikelets terete, terminal, clustered or 

 BoUtary, subtended by a 1-3-leaved involucre; scales in a spiral, 

 deciduous, all subtending perfect flowers; perianth of a single 

 hyaline brad between the flower and the rachilla; bristles none; 



nuns 1-3; style 2-cleft, deciduous, not swollen at the base; 

 akene oblong, turgid or lenticular. 



Hemicarpha aristulata (Coville) A. Nelson. Tufted, glabrous, the nu- 

 merous stems 5-8 cm. tall, erect or spreading; leaves narrow, involute, the 

 irved blades 1-3 cm. long, as long as or longer than the sheaths; spikelets 

 id, obtuse, solitary or two in a cluster, 2-4 mm. long; involucral bracts 3, 

 the uppermost 1-3 cm. long, the others much shorter; scales 1-1.5 mm. long, 

 broadly obovate, the abruptly-acuminate recurved apex as long as the body; 

 akene oblong, ovate or obovate, 0.5 mm. long, with a short beak, the surface 

 \iry minutely and regularly hexagonal-reticulate and rugose; styles shorter 

 than the akene, 2-cleft half-way to the base; hyaline bract triangular-ovate. 

 Wry rare on the banks of Snake River at Almota. The species has the habit 

 of //. subsquarrosa Nees, but the heads of H. occidentalis Gray. 



Family 17. ARACEAE. Arum Family. 



Plants with acrid or pungent juice and simple or compound 

 leaves; flowers crowded on a spadix, perfect, monoecious or 

 dioecious; spathe present or none; perianth of 4-6 sepals or 

 none; fruit usually a 1-4-celled 1 -seeded berry. 



70. LYSICHITON. 



Acaulescent swamp herbs with large leaves from a thick 

 horizontal rootstock; spathe sheathing at base, with or without 

 a broad colored lamina, at first enveloping the cylindrical spadix 

 ich later becomes long-exserted on a stout peduncle; flowers 

 perfei t, crowded, covering the spadix; perianth 4-lobed ; stamens 

 4, opposite the perianth-segments; ovary 2-celled, 2-ovuled; 

 fruit fleshy, Bomewhat immersed in the rachis and coalescent. 



Lysichiton camtschatcense (L.) Schott. Yellow Skunk Cabbage. Leaves 



in. long, oblong, acute or acutish, narrowed at base into a short 



>le; spathe golden-yellow, the blade oblong, acute, narrowed into 



Hole; peduncle stout, 20-30 cm. long; spadix cylindric, in fruit 



In swamps, the brilliant malodorous flowers appearing before 



