6 NYCTAGINACE^E. Boerhaavia. 



petioles, minutely black-dotted, lighter colored beneath : panicle very open : bracts minute and 

 liowers very small : fascicles usually 3-6-flowered : fruit sessile or shortly pedicellate, nearly 2 

 lines long, glabrous, clavate, truncate at top, 5-costate and rugulose between the ribs. Choisy, 

 1. c. 450. Across the continent from the Pacific to Florida and the West Indies. A form is 

 common in Lower California, Arizona and New Mexico, usually slender and very scabrous below, 

 mostly with narrow leaves on very short petioles. 



* * Flowers spicate. 



B. SPICA.TA, Choisy, 1. c. 456. A low annual, resembling B. erecta, but the flowers mostly 

 solitary and scattered along the slender branches : fruit very shortly pedicellate, glabrous, rounded 

 at the apex. Lower California to Arizona and New Mexico. 



* * * Flowers umbellate. 



B. SCANDENS, Linn. Perennial, glabrous : leaves cordate or ovate, acute or acuminate, 1 or 2 

 inches long, on rather short petioles : umbels 6 -10-flowered on simple axillary peduncles, or the 

 inflorescence somewhat paniculate : bractlets a line or two long : pedicels slender, 2 to 6 lines 

 long ; flowers greenish, 2 to 4 lines long including the base : stamens exserted : fruit glabrous, 

 linear-clavate, terete and obscurely 10-costate, black-glandular toward the apex. Choisy, 1. c. 

 454. B. Grahami, Gray, Am. Journ. Sci. 2 ser. xv. 323. From Peru to the W. Indies, New 

 Mexico and Southern Arizona. 



5. HERMIDIUM, Watson. 



Characters as in Mirabilis, but the involucre of distinct broad foliaceous bracts, 

 each adnate to the pedicel of a single flower. Perianth campanulate-funnelform. 

 Stamens 5 to 7. Flowers in capitate terminal and axillary racemes. A single 

 species. 



1. H. alipes, Watson. Perennial, stout and fleshy, glabrous and glaucous, the 

 stems branched and ascending, a foot high : leaves broadly ovate to lanceolate, acute 

 or obtuse, somewhat cordate at base, 1 to 2| inches long, on very short thick peti- 

 oles : heads about 6-flowered, on short peduncles : bracts cordate-ovate, somewhat 

 membranaceous and more or less colored, 6 to 10 lines long, acute : perianth about 

 equalling the bract, slightly 5-lobed, light purple : stamens and style not exserted : 

 fruit globular, smooth. Bot. King Exp. 286, t. 32. 



On low foothills in Northwestern Nevada, near the Humboldt and Truckee Rivers, Watson, 

 Lemtnon. Flowering in May. 



ORDER LXXVII. POLYGONACE^I. 



Herbaceous or woody plants, with tumid joints, alternate and entire leaves (ex- 

 cept in Pterostegia), or sometimes verticillate and often only radical, with sheathing 

 stipules or none ; flowers mostly perfect, on jointed pedicels ; calyx more or less pet- 

 aloid, usually persistent about the free 1 -celled 1-ovuled ovary; stamens mostly 4 to 

 9, perigynous, with oval or oblong anthers ; styles 2 to 4, distinct or somewhat con- 

 nate, opposite the angles of the ovary ; seed erect, orthotropous, with the embryo 

 curved and at one side of the usually mealy albumen, or straight and within it. 

 Flowers rather small, the perianth of 3 to 6 distinct or more or less united segments, 

 the inner ones or all usually petaloid ; fruit an "akene, compressed or 3 - 4-angled 

 or -winged. 



An order of 30 genera and 700 species, mostly belonging to northern temperate regions, the large 

 tribe of Eriocionece restricted almost exclusively to Western America. This tribe, largely repre- 

 sented in our flora, is wholly valueless except as a few species may become cultivated for orna- 

 ment. The larger group of Polygonece furnishes the officinal Rhubarb, as well as the garden 

 vegetable of the same name (species of Rheum), and the Buckwheat (Fagopyrum esculentuiri). 

 Many species abound in oxalic acid, some have been used in dyeing, and the roots are frequently 

 medicinal. 



