572 POLYGON ACE M ERIOGONUM 



slender dcflexed pedicels an inch long or less, 5-cleft to near the middle: 

 flowers whitish, campanulate, half a line long, fiddle-shape. On dry plains, 

 eastern Oregon to Nebraska and New Mexico. 



* * Annuals, branching from the base, with leaves developed at 

 the nodes in the axils of ordinary triangular bracts : flowers minutely 

 glandular. 



E. angnlosuiu Benth. Trans. Linn. Soc. xvii, 406, t. 18. Floccose- 

 woolly, or at length glabrate: stem erect, 4-12 inches high, leafy, branch- 

 ing into a repeatedly di-or trichotomous panicle; the branches acutely 4-6 

 angled : radical leaves spatulate or rounded, the cauline oblong-linear to 

 lanceolate : pedicels 6-12 lines long, widely spreading: involucres short- 

 campanulate or hemispherical, minutely glandular or almost smooth, soli- 

 tary, many-flowered, 5-toothed becoming dilated in fruit : flowers very obtuse 

 at base, a line long, on short pedicels, rose-color or white, deeply 5-parted, 

 the outer segments ovate, the inner at length longer, lanceolate-oblong. 

 Eastern Oregon to California and Utah. 



* * * Tall stout white-tomentose annuals, with leafy simple stems, 

 naked above: inflorescence cymose : involucres turbinate-campanulate, 

 shortly pedicelled : flowers white, nearly glabrous : sepals very unequal. 



E. aimunm Nutt. Trans. Am. Phil. Soc. Ser. 2. v, 164. Flowers 

 tomentose throughout: stem 1-3 feet high, leafy below : leaves oblong-lanc- 

 eolate or oblanceolate, narrowed at base to a petiole, the margins somewhat 

 revoluteor crisped: involucres turbinate 1-1^ lines long secund, erect, 5 

 toothed : calyx %-l line long, the segments obovate. On dry plains Idaho 

 to Nebraska and Texas. 



3 Involucres cylindric-turbinate, more or less strongly 5-(5 

 nerved, often becoming costate or angled, with as many short 

 erect teeth, mostly sessile in heads or clusters, scattered in cymes 

 or along virgate panicled branches, always erect, 13 lines long: 

 bracts ternate, connate at base, usually short, acute and more or 

 less rigid : flowers not attenuate at base : achenes usually glabrous. 



* Cespitose densely tomentose perennials with short closely branch- 

 ed caudex : involucres a single head or short cymose umbel on the 

 naked peduncle : outer sepals broad and somewhat cordate, the inner 

 much narrower: ovary scabrous above. 



E. ovalifolium Nutt. Journ. Philad. Acad. vii, 50, t. 8. Densely 

 white-tomento&e and silvery : stems very short and deprcssed-cespitpse, 

 perennial ; leaves broadly oval or oblong, the blade 3-10 lines long, acutish, 

 abruptly narrowed to a long slender petiole, crowded upon the numerous 

 short branches: scapes 3-9 inches high simple, naked, bearing a single head 

 of 3-8 closely sessile 5-8 toothed involucres : calyx very glabrous, yellow or 

 rose-color, becoming thin and scarious, after flowering, the segments very 

 unequal, the outer very broadly oval, cordate at base: the inner spatulate, 

 emarginate. On dry hillsides, eastern^Brit. Columbia to California and 

 the Rocky Mountains. 



Var. proliferum Watson Proc. Am. Acad. xii, 63. Larger than the 

 type, the involucres loosely cymose-umbellate. With the type. 



E. vineum. Small Bull. Torr. Bot. Club xxv, 45. Closely white-tomen- 

 tose up to the inflorescence : perennial from a stout tap-root: stems branch- 

 ing, the branches tufted, clothed with the persistent leaf bases : leaves 

 crowded, the blades suborbicular or broadly oval, 3-5 lines long obtuse or 

 rounded at the apex, abruptly narrowed or truncate at base: on petiol ea 

 often as long as the blade : scapes erect, 1-4 inches long, simple : involucre s 



