Hitchcock — The Grasses of Hazvaii 209 



43. DISSOCHONDRUS (Hillebr.) Kuntze. 



Spikelets subtended by a single persistent bristle (sterile branohlet), awnless, consisting 

 of 2 membranaceous glumes and 2 cartilaginous florets, the 2 fruits similar and closely con- 

 tiguous by their flat inner faces; first glume broad, about one-fourth as long as the spikelet; 

 second glume a little longer than the 2 florets ; lemmas cartilaginous-indurate, smooth, nerveless, 

 the margins inrolled over the cartilaginous palea. the 2 fruits similar, the lower a little longer 

 but rising to the same height. Rather tall perennial grasses with flat petioled blades, auriculate 

 sheaths and slender spikelike panicles. 



The genus is based on Setaria biflora Hillebr., the only species, and was 

 first described as a subgenus of Setaria by Hillebrand." Ktmtze"" raised this 

 subgenus to generic rank but inad\-ertentlv gave the species as "Dissocliojidnis 

 biftdiis OK. = Setaria bifida Hillebr." 



I. Dissochondrus biflorus (Hillebr.) Kuntze: Hack, in Engl. & Prantl, Pflanzenfam. i: Nachtr. 



41. 1897. 



Setaria hiflora Hillebr. Fl. Haw. Isl. 503. 1888. 



Culms 60 to 120 cm. tall, compressed, puberulent at the nodes; sheaths glabrous, com- 

 pressed-keeled, extending at the summit beside the petiole into 2 membranaceous, more or less 

 deciduous or fragile auricles as much as 4 cm. long, especially prominent on the innovations ; 

 ligule short, scarious ; blades flat, firm, 15 to 30 cm. long, i to 2 cm. wide, gradually acuminate, 

 contracted at base into a petiole, glabrous, scaberulous on the margin and toward the tip : 

 panicle cylindric. slender, spikelike. 10 to 20 cm. long, somewhat loosely flowered, more or less 

 interrupted at base, the branches short and appressed, the axis puberulent ; bristles flexuous, 

 antrorsely scabrous, 5 to 10 mm. long, solitary below each spikelet or wanting below some of 

 the spikelets ; spikelets 2.5 to 3 mm. long, pointed, glabrous ; first glume broad, obtuse, one- 

 fourth to one-third as long as the florets, puberulent, scarcely nerved; second glume pointed 

 beyond the florets, puberulent. faintly 5-nerved : florets yellowish, smooth and polished, about 

 2 mm. long, slightly pointed, the tip minutely puberulent (fig. loi'). 



Rocky slopes in partial shade. Originally described from Lanai. 

 Oahu: West of Schofield Barracks, Hitchcock 13952. ]\Iakaleha Ridge, 



Rock 1 708 1. 

 Molokai : Puu Kolekole, Forbes 219. 



Peituisetuiii inacrostacJiyuni (Brong.) Trin. was found near a garden, Hilo, where the 

 species was cultivated for ornament (Hitchcock 14.175). It is a tall graceful perennial with flat 

 blades 1.5 to 2.5 cm. wide, and a feathery purplish panicle 15 to 20 cm. long, the numerous 

 bristles 2 to 3 cm. long. 



44. CENCHRUS L. 



Spikelets solitary or few together, surrounded and inclosed by a spiny bur composed of 

 numerous coalescing bristles (compound sterile branchlets), the burs sessile or nearly so, falling 

 with the spikelets and permanently inclosing them, the seed germinating within the old involucre, 

 the spines usually retrorsely barbed. Annual or perennial, commonly low branching grasses, 

 with flat blades and racemes of burs, the burs readily deciduous. 



Plants perennial; burs fusiform i. C. agrimonioides. 



Plants annual ; burs globular. 



&' 



Foliage glabrous 2. C. echinatus. 



b 



Foliage pubescent 3. C. hillebrandianus. 



'"Op. cit., p. 503. 1888. 



""Kuntze, Otto., Revisio gcnenim plantanim, Vol. 2. p. 770, Stuttgart & Tubingen, 1S91. 



[hi] 



