574 POLYGONACE.E EBIOGONUM 



oles : peduncles 1-4 feet high, rigid and rush-like : inflorescence a very dif- 

 fuse panicle: involucres glabrate, or glabrous, few, cylindrical or turbin- 

 ate-campanulate, repandly ,5-toothed many-flowered, gathered in heads or 

 clusters, sometimes only in pairs, or solitary in the forks: flowers white or 

 rose-color a little hairy at base the segments ovate-oblong, nearly equal. 

 On barren rocky places, eastern Washington to California. 



- *- Leaves not fascicled : bracts small very rarely foliaceous below : 

 involucres mostly solitary in a repeatedly di- or trichotomous corymb- 

 like cyme. 



* Perennials, woody and diffusely much branched, leafy below. 



E. microthecum Nutt. Jour. Acad. Phila. ser. 2, i, 172. More or less 

 floccose-tomentose throughout: steins erect or ascending, branching, 

 especially from the base, 6-12 inches high : leaves oblong or oblanceolate, 

 obtuse at the apex, narrowed into short petioles, 6-12 lines long, the upper 

 bract-like: inflorescence compoundly cymose: involucres turbinate 1^ 

 lines long: flowers yellow, pink or white, campanulate, at length constrict- 

 ed near the middle. Eastern Washington to California and Nebraska. 



E. corymbosum Benth. in DC. Prodr. xiv, 17. Densely floccose-to- 

 mentose throughout : stems erect, branched 6-12 inches high : leaves oblong, 

 obtuse at the apex, narrowed at base, petioled, 6-18 lines long, their margins 

 more or less crisp : inflorescence compoundly cymose : involucres short-cam - 

 panulate, 5-toothed, about 1)^ lines long, the teeth subacute flowers broadly 

 campanulate, 1-1 K lines long, constricted near the middle, the segments 

 fiddle-shaped, emarginate, the 3 inner ones shorter than the outer ones . 

 Eastern Washington to Nevada and Kansas. 



++ *+ Perennial : less woody and more shortly branched at base : 

 leaves mostly narrow : sepals nearly equal. 



E. campanulatum Nutt. 1. c. 163. Stems short, thick and woody 

 more or less tomentose : leaves crowded, narrowly oblanceolate, spatulate 

 or nearly linear, 1-3 inches long, obtuse at the apex, narrowed into long 

 petioles, white-tomentose on both sides, the margins sometimes revolute: 

 peduncles erector nearly so, glabrous, 4-12 inches high : inflorescences com- 

 poundly cymose: involucres oblpng-turbinate, about a line long, with 5 

 obtuse teeth : flowers yellow, ovoid-cam panulate, about a line long, the 

 segments oblong or fidclle-shaped, emarginate. Eastern Oregon to Nebraska 



*-*-!- Involucres sessile and solitary along the ascending and 

 usually long-virgate branches of the open naked panicle: flowers 

 glabrous. 



* White-tomentose perennials, leafy below: panicles sparingly 

 branched, usually virgate: involucres" tomentose, the teeth not 

 margined. 



E. strictum Benth. Branches very short: leaves small, ovate to oblan- 

 ceolate, on long slender petioles : peduncles very slender, glabrate above : 

 panicle twice or thrice divided, with 1-3 involucres on the short branches : 

 involucres glabrate, \y z lines long: flowers white to rose-color, \% lines 

 long. In the Blue Mountains of Oregon. 



* +* Annuals : leaves usually rosulate at the base, sometimes 

 occuring at the nodes. 



E. virgatum Benth. in DC. Prodr. xiv, 16. Usually white-tomentose 

 throughout : leaves oblong, an inch long, on slender petioles : peduncles 

 simple, or with a few erect virgate branches, 1-2 feet high : involucres re- 

 mote, 2 lines long, lomentose, the 5 teeth very short: flowers a line long 

 rose-color to white or yellow, glabrous, outer segments broadly ovate, 

 cuneately narrowed at base, the inner about as long, spatulate- oblong. In 



