354 POLYGONACEAE (BUCKWHEAT I^AMILY) 



attenuate, viUous-canescent. — SaLiidy woods and barrens, " s. Mo." to Fla. 

 and Tex. 



2. E. Alldni Wats. Perennial, erect ; leaves oblong, canescent-tomentose 

 beneath, flocculent or glabrate above, the lower rather abrupt at base ; inflores- 

 cence leafy ; sepals elliptical, yellow, nearly glabrous. — Dry soil, mts. of W. 

 Va. and Va, 



2. OX'f'RIA Hill. Mountain Sorsbl 



Outer sepals smaller and spreading, the inner broader and erect (but un- 

 changed) in fruit. Stamens 6. Stigmas 2, sessile, tufted. Achene lenticular, 

 thin, flat, much larger than the calyx, surrounded by a broad veiny wing. 

 Embryo straight, in center of the albumen, slender. — Low alpine perennial, 

 with round-kidney-form and long-petioled leaves chiefly from the rootstock, 

 obliquely truncate sheaths, and small greenish to crimson flowers clustered in 

 panicled racemes on a stoutish 1-2-leaved stem. (Name from (5fi>s, sour^ from 

 the acid leaves.) 



1. 0. digyna (L.) Hill. Alpine regions of the White Mts., N. H., and far 

 northw. ; Rocky Mts. (Eu.) 



3. RtTMEX L. Dock. Sorrel 



Calyx of 6 sepals ; the 3 outer herbaceous, sometimes united at base, spread- 

 ing in fruit ; the 3 inner larger, somewhat colored (in fruit called valves) and 

 convergent over the 3-angled achene, veiny, often bearing a grain-like tubercle 

 on the back. Stamens 6, Styles 3 ; stigmas tufted. Embryo slightly curved, 

 lying along one side of the albumen, slender. — Coarse herbs, with small and 

 homely (mostly green) flowers, which are crowded and commonly whorled in 

 panicled racemes ; the petioles somewhat sheathing at base. (The ancient 

 Latin name ; of unknown etymology.) 



[6. None of the leaves halberd- op arrow-shaped &. 

 6. Valves entire or denticulate, 8-27 mm. broad c. 

 c. Grains of ft'ulting calyx 0, or single and minute, not one third as 

 long as the valves. 



Valves very large, 15-27 mm. broad 1. A. venosus. 



Valves 4-7 mm. broad. 



Pedicels with tumid joints , , % R. Patientia. 



Pedicels obscurely Jointed 3. R. ocoidwUaUa. 



V, Grains 1-S, well developed, mostly one half to three fomrths as 

 loi^g as the valves ef . 

 d. Pedicels filiform, curved or flexuous e. 

 (^. Leaves crisped on the margin. 



Grains chiefiy plump and rounded at both ends • , b. B. efispua. 



Principal grains tapering at summit 6. B, elongaius, 



6. Leaves nat /. 

 /. Pedicels with tumid joints, rarely exceeding the coriaceous 

 greenish, straw-colored, or dull brown calyx. 

 Grains 3, 

 As broad as or broader than the wings of the valves . 7. B, pallidus. 

 Narrower than the wings ,,.,... S. B. m&cicanus. 



Grain 1 9, B. altiesimuB, 



f. Pedicels obscurely Jointed, mostly exceeding the membra- 

 nous finally purplish calyx. 



Grains 3 ^, B, Britannica. 



Grain solitaiy . . 3. ^. occidentnlia. 



d. Pedicels clavate, defiexed, straightlsh and slightly rigid, 2-3 



times as long as the subacuminate valves . . . . 10. ^. verHciUatua. 

 h. Valves entire or nearly so, scarcely 2 mm. broad, grain-bearing . 11. B. conglomeratus. 

 b. Valves with long sharp salient teeth at least near the base. 



Perennial; pedicels filiform, longer than the subherbaceous valves 12. B. obtusifolitts. 

 Perennial: pedicels thick, shorter than the thickish indurated 



valves %Z. B. pvZoher, 



Annual ; teeth of the valves bristle-form 14. .S. peraiearioidM. 



a. Some or all the leaves halberd- or arrow-shaped. 



Valves much exceeding the ft'ult; leaves arrow-shaped . . .15. R. Acetosa. 

 Valves much exceeding the IVnit; leaves halberd-shaped . , .16. i2. haatatulu^. 

 Fruit exaerted from the minute scarcely changed calyx , . . VI. B. Acetoaella. 



