106 POLYGONACEJE. (BUCKWHEAT FAMILY.) 



G-parted or deeply 6-cleft. Stamens 9. Akene triangular. — Herbaeous or somewhat 

 woody plants, usually with a woolly or scurfy pubescence; the entire leaves without 

 stipules and mostly radical; juice frequently acid. Over 80 species grow west of the 

 Mississippi. 



§ 1. Involucres usually deeply 5-D-de/t umbellate, icith spreadln'j or reflexed lobes ana 



many fioioers. 



1. E. polyanthum, Bentli. Leaves mostly virticillate, ovate or oblong, acute, 

 white-woolly; i)eduncles solitary or few, and umbellate; flowers yellow. 



2. E. compositum, Dougl. The scape-like peduncle rising from the prostrate 

 stem bearing a compound many-rayed umbel involucrate with linear-lanceolate bracts; 

 involucre about 5-cleft; flowers whitish; radical leaves oblong ovate and cordate, densely 

 tomentose beneath. 



3. E. umbellatum, Torr. Scape-like peduncle rising from prostrate stem 4 to 12 

 inches high, naked except the verticillate bracts; umbel usually simple; leaves broadly 

 spatulate or oval, white-woolly beneath; involucre 6-8-cleft; flowers yellow or white. 



§ 2. Involucres sessile, capitate ; the usually naked globose heads solitary or subumhellate 

 upon a naked simple peduncle; involucres short-campanulate, truncate, the 5-8-teeth 

 united by a membrane; flowers white, bractlets plumose at length exserted. 



4. E. latifolium, Sm. Leaves 1 to 2 inches long, oval, base broad and rounded or 

 cordate; involucres woolly, 5-toothed. 



5. E. oblongifolium, Benth. Leaves oblong and oval, base usually acute; involu- 

 cres smooth, 6-8-toothed. 



§ 3. Involucres truncate, subdentate, in small bracteate heads terminating the forking or 



cymose umbellate peduncles. Shrubby, leafy. 

 C. E. parvifolium, Sm. The small ovate or ovate-lanceolate leaves very numerous; 

 involucres often sub racemose along the peduncle; flowers white or pinkish. 



§ 4. Involucres 5-G-toothed, cymose on a naked peduncle, the pedicels short or none. 



7. E. truncatum. Torr. & Gr. Loosely floccose-wooUy, 1 ft. high; stems leafy 

 only below; involucres truncate. 



§. 5. Involucres sessile, along one side of the usually virgate branches of the jjanicle, 



mostly small or narroiv. 



8. E. virgatum, Benth. Slender stem siiaringly leafy; involucres 2 to 2i lines 



long, 5-toothed. Very white-woolly. 



Ckorizanlhe is tUetinguished by a 1-flowered involucre. 



Pterostegia has opposite lobed-leaves ■with axillary flowers. A small under-herb. 



Laurac'E^ is represented by Umbellaria [Oreodaphne) Californica, the California 

 Laurel. 

 TiiYMELACEiE is represented by Dirca j^dustris or leatherwood. 



