11 10 ADDITIONS AND CORRECTIONS 



Page 



finely villous beneath, 7 — 15 cm. long; involucre of 2, broad, laciniate, 

 nearly distinct bracts, downy and glandular-bristly; nut compressed, 

 12 mm. high, light brown. Thickets: Ale. — Sask. — S. D. (Black Hills) — 

 Kans. — Fla. Austral — Boreal. Mr-Ap. 



207 Under C. rugulosa add the synonym Celtis reticulata vestita Sarg. 

 207 After C. rdinduta insert; 



4a. Celtis viHosula Rydberg, sp. nov. Shrub or small tree; l)ranches 

 light brown, conspicuously villous when young; petioles 3-5 mm. long, 

 villous; leaf-blades broadly and oblitiuclj' ovate, 3-4 cm. long, 1.5-2.5 cm. 

 wide, dark and grayish green and pustulate hispidulous above, pale and 

 short-hirsute on the veins beneath, acute, subentire, more or less cordate 

 at the base; peduncles about 8 mm. long, villous; fruit (unripe) 

 5-6 mm. long, suljglobcse, yellowish-green; style-branches 4 mm. long. 

 Utah (without definite locality), M. E. Jones. 



224 In the 5th line of the description of E. nebraskense for "2-3 cm." read 

 "2-3 mm." 



232 After 16 R. mexicanus insert: 



16a. Rumex Britannica L. Perennial; stem 1-2 high; leaves oblong- 

 lanceolate, erose-crenate on the margins, the lower petioled, acute at 

 each end, 3-6 dm. long, the middle ones truncate or cordate at the base; 

 whorls of flowers crowded, in a large panicle; outer perianth lol:)es in 

 fruit orbicular or round-ovate, obtuse, finely reticulate, all three tubercle- 

 bearing. Wet places: Newf. — Minn. — Kans. — N. J.; Utah; adv. or nat. 

 from Eur. Jl-Au. 



234 Before P. buxiforme insert: 



2a. Polygonum achoreum Blake. Annual; stem ascending, much 

 branched, 1.5-4 dm. long, striate, glabrous; ochreae scarious, whitish 

 with a brown base, soon lacerate, 4-9 mm. long; leaves crowded, elliptic, 

 oval, or obovate, rounded at the apex, 7-22 mm. long, 4-10 mm. wide, 

 bluish-green; perianth bluish-green, in fruit 3.5-4 mm. long, the outer lobes 

 with or without a narrow pale margin, the inner white- or pink-margined; 

 achenes included, obscurely punctate, dull, 2.5 mm. long. Waste places 

 and sandy soil: Que. — Vt. — Sask. — Mont. — Kans. — Mo. Jl-Au. 



236 Instead of the first part of the Key insert: 



Racemes spikelike, terminal only, solitary or 2, rarely 3 or 4; plant perennial 

 iisiially witli both terrestrial and aquatic forms. 

 Racemes broadly oblong, roimded at the apex; leaf-blades in the terrestrial 

 form lance-linear or lance-oblong; in the aquatic form oblong, glabrous, 

 broadest at the middle, scarcely ever siibcordate at the ba,se: ochreae 

 of the upper leaves m the terrestrial form usually with foliaceous 

 dilated margins. 

 Pedimcles glabrous or in the terrestrial form sometimes sparingly hirsute; 

 leaves dark green and especially in the aquatic form shining above. 

 Racemes 15-18 mm. thick; leaf-blades in the terrestrial form lancc- 

 oblong; in tlie aquatic form broadly oblong, usually H-12 as broad 

 as long, trmicate or abruptly contracted at the base, and obtuse 

 at the apex, rarely acute at each end, glabrous; upper ochreae in the 

 aquatic form inflated, membranous. 1. P. pst/crnplnlo. 



Racemes 10-15 mm. tliick; leaf-blades in the terrestrial form lance- 

 oblong; in tlie aquatic form narrowly oblong, J^-J^ as broad as long, 

 acute or aciUish at eacli end; peduncles in tlie terrestrial form often 

 with a iCW hairs; ochreae ui the aquatic form not filiated. 



la. P. fluilans. 

 Pedimcles in the terrestrial form distinct Ij- hirsiitulous ; leaf-blades light 

 green, in the terrestrial form lance-oblong, pubescent on both sides; 

 in the aquatic form glabrous and dull above; floweruig raceme 10-15 

 mm. thick. 2. P. itebraakrnsis. 



Racemes linear, tapering to the apex; pedimcles in the terrestrial form 

 pubescent or glandular, in the aquatic form .sometimes slightly so; 

 leaf-blades broadest near the base, in the terrestrial form of a lanceo- 

 late type, acuminate, in tlie aquatic form ovate, acute at the apex, 

 often cordate or subcordate at the base. 

 Raceme about 3 cm. long or less; flowers 3—4 mm. long; pedmicles in the 

 terrestrial form luspidulous, scarcely glandular; leaf-blades in tills form 

 linear-lanceolate, usually 3 cm. wide; ochreae sometimes with a folia- 

 ceous border. 2a. P. mesochora. 



