MANUAL OF THE GRASSES OF THE UNITED STATES 27 



DESCRIPTIONS OF GENERA AND SPECIES 



TRIBE 1. BAMBUSEAE 



1. ARUNDINARIA Michx. Cane 



Spikelets 8- to 12-flowered, large, compressed, the rachilla disarticulating 

 above the glumes and between the florets; glumes unequal, shorter than the 

 lemmas, the first sometimes wanting; lemmas papery, rather fragile, about 

 11-nerved, acute, acuminate, mucronate or awn-tipped; palea about as long 

 as the lemma or a little shorter, prominently 2-keeled, deeply sulcate between 

 the keels; rachilla joints rather thick, appressed-hirsute ; stamens 3; caryopsis 

 narrowly elliptic, terete, 1 to 1.2 cm. long. Shrubs or tall reeds with extensively 

 creeping horizontal rhizomes 5 to 10 mm. thick, the woody perennial branching 

 culms erect, 2 to 5 m., sometimes to 8 m., tall and 2 cm. thick, freely branch- 

 ing, the flowering branchlets borne in fascicles on the main culm or on primary 

 branches, their sheaths bladeless or nearly so, flowering shoots also arising 

 from the rhizomes, their sheaths bladeless; flowering at infrequent intervals, 

 usually each species over a wide area simultaneously, the flowering period 

 apparently continuing for about a year; the flowering culms apparently 

 dying after setting seed; sterile branches numerous and repeatedly branching, 

 the basal shoots and primary branches with 6 to 10 loose, papery culm- 

 sheaths with narrow rudimentary blades 2 to 20 mm. long, not petiolate at 

 base, and 4 to 10 large petiolate tessellate blades toward the ends, their 

 sheaths overlapping, the upper blades crowded, the lower papery sheaths 

 finally falling, the leaf-sheaths bearing several flat scabrous bristles at the 

 summit, these readily falling in age. Type species, Arundinaria macrosperma 

 Michx. (A. gigantea). Name from Latin Arundo, a reed. 



Primary branches erect or nearly so, the individual culm with its branches oblong-linear in 

 outline; spikelets usually rather loose; lemmas appressed-hirsute or canescent, at least 

 toward the base, greenish tawny to bronze-russet 1. A. gigantea. 



Primary branches ascending at an angle of about 45°, the individual culm with its branches 

 broadly lanceolate in outline; spikelets rather compact; lemmas glabrous or obscurely 

 pubescent at base only, usually livid-purple 2. A. tecta. 



1. Arundinaria gigantea (Walt.) 



Muhl. Giant cane. (Fig. 1.) Culms tessellate, acuminate, pubescent to 



as much as 2 cm. thick and 2 to 8 m. glabrous on the lower surface, puberu- 



tall, smooth; lower sheaths about half lent to glabrous on the upper, the 



as long as the internodes, finally fall- margin finely serrulate; blades of ulti- 



ing, the upper 6 to 10 sheaths striate, mate branchlets much smaller, often 



tessellate, usually hirsute, becoming crowded in flabellate clusters, com- 



glabrous or nearly so, densely ciliate, monly glabrous or nearly so ; flowering 



canescent at base, the 10 to 12 bris- branchlets finally crowded toward the 



ties at the summit 5 to 9 mm. long, ends of the branches, the racemes or 



these often borne from the margin of simple panicles with few to several 



a rather firm auricle, this sometimes spikelets on slender angled pedicels 2 



prominent but often obscure or want- to 30 mm. long, hirsute to nearly 



ing, a dense band of stiff hairs across glabrous; spikelets 4 to 7 cm. long, 



the collar; ligule firm, scarcely 1 mm. about 8 mm. wide, mostly 8- to 12- 



long; blades of main culm and pri- flowered, rather loose; glumes distant, 



mary branches 15 to 27 cm. long, 2.5 acuminate, pubescent, the lower min- 



to 4 cm. wide, rounded at base (peti- ute, sometimes wanting; lemmas 



ole 1 to 2 mm. long), strongly finely broadly lanceolate, keeled, mostly 1.5 



