1038 APPENDIX. 



or ovate to broadly ovate; the terminal branchlets regularly producing 

 innovations the second and sometimes the third season, the older foliage 

 branches ultimately spreading and becoming lax; leaves of the primary 

 axis in 6-8 rows, from ovate through lanceolate-acute to acuminate, those 

 of the subterminal and terminal branchlets in four rows, glaucous, bluish 

 green, acuminate, appressed, those of the under row differing scarcely at 

 all from those of the other three rows, the leaves of the lateral rows some- 

 what incurved underneath; peduncles terete, glaucous, 50-60 mm. long to 

 the first forking, usually twice forked, the second 8-18 mm. distant from 

 the first, spreading and curving upward; strobiles two, three or usually 

 four, 20-28 mm. long, the sporophylls broadly depressed-ovate, truncate 

 at the base, the lateral margins variously toothed, suddenly contracted 

 into a subulate scarious tip; sporangium reniform, opening by a transverse 

 slit along the top; spores ripening early in August. (L. Chamaecyparissus 

 A. Br.) Differs from L. complanatum, with which it has been confused, 

 in its subterranean habit, its uniform leaves, its method of branching, and 

 in its distant clusters of strobiles. Me. to Ga. and Minn. 



P. 29. Additional species and subspecies of Isoetes have been described 

 by A. A. Eaton in " Fern-studies " and in " Proceedings of the Biological 

 Society of Washington." 



P. 40, before description of Sparganium simplex, insert: 

 2a. Sparganium Americanum Nutt. SIMPLE-STEMMED BUR-REED. Sim- 

 ilar to S. androcladum, but the stem simple, the lower heads of the inflores- 

 cence merely peduncled. Leaves drying green, the upper with more or 

 less sac-like bases and broad hyaline-scarious margins; nutlets slightly 

 angled, each gradually narrowed into a stout conspicuous style. In low 

 grounds or ponds, Ont. to Br. Col., Penn. and the Ind. Terr. Summer. 



P. 40, after Sparganium minimum, add : 



5. Sparganium hyperboreum Laest. NORTHERN BUR-REED. Stem 2-3 

 dm. high; leaves shorter and narrower than those of S. minimum, 1-3 

 mm. wide; inflorescence 1.5-2.5 cm. long; pistillate heads I or 2, sessile, 

 or the lower one short-peduncled; ripe fruiting heads 5-10 mm. in diam- 

 eter; nutlets oblong, obscurely triangular at the summit; stipe very short, 

 stigma oval, oblique, minute, sessile, or nearly so. Lab. and Hudson 

 Bay. Also in northern Europe. Summer. 



P. 49. Additional species and subspecies of Potamogeton have been de- 

 scribed by Arthur Bennett in recent papers published in the " Journal of 

 Botany." 



P. 68, after Erianthus brevibarbis Michx., insert: 



4a. Erianthus contortus Ell. TWISTED-AWNED PLUME-GRASS. Culms 

 1-2 in. tall, the summit and panicle-axis glabrous, or nearly so; leaves 

 1.5-8 dm. long, 5-20 mm. wide; panicle 1.5-3 dm. long, 3-5 cm. wide; 

 spikelets crowded, exceeding the basal hairs and about one-half again as 

 long as the internodes, the outer scales 7-7.5 mm. long, the fourth scale 

 2-toothed at the apex, the awn 1.5-2 cm. long, the included portion often 

 a little spiral at the base, the remainder loosely spiral. In pine woods, 

 Del. to Fla. and Miss. Sept. and Oct. Differs from E. brevibarbis in hav- 

 ing the spikelets smaller and the exserted portion of the awn loosely spiral. 



P. 70, after Andropogon Virginicus L.. insert: 



4a. Andropogon tetrastachyus Ell. FOUR-SPIKED BEARD-GRASS. Culms 

 tufted, 8-15 dm. tall; sheaths, at least the lower ones, densely villous, with 

 dark hairs; leaves 4 dm. long or less, 2-4 mm. wide, the lower ones villous 

 on both surfaces toward the base; spathes usually 3-4 cm. long, extending 1 

 beyond the racemes; racemes usually in fours, 3-4 cm. long; sessile spike- 



