16 SPRING FLORA 



polygamous). Calyx 3-cleft; more or less persistent. 

 Corolla none. Stamens 4-12, borne on base of calyx. 

 Pistil of 2-3 stigmas, 2-3 styles, a "superior" 1-eelled 

 and 1-seeded ovary that ripens into a 3-angled achene. 



Stipules wanting; stamens 9; flowers mostly involu- 



crate 1. Eriogouum 



Stipules conspicuous; stamens 4-8; flowers not involu- 



crate 2. Rumcx 



1. ERIOGONUM. 



Annual or perennial, some species woody at base. Stems 

 branched or unbranched, often tufted. Leaves basal, alternate, 

 opposite or whorled. Inflorescence various. Flowers small; 

 perfect; usually involucrate. Calyx 6-cleft or -parted, usually 

 bright-colored; persistent about the achene. Stamens 9, in- 

 cluded or exserted. Styles 3; stigmas capitate. Achenes 3- 

 angled (rarely 3-winged). 



Flowers not stalk -like at base 1. E. ovalifolium 



Flowers stalk-like at base. 



Peduncles leafy-bracted; leaves narrow, tomentose 



on both sides 2. E. heracleoides 



Peduncles naked or 1-bracted; leaves broader, gla- 

 brous or glabrate above 3. E. umbellatum 



1. E. ovalifolium Nutt. Silver Plant. Low and caespitose. 

 perennial from a short caudex; densely white-woolly. Leaves 

 round or oblong. Involucres in a single compact head. Bracts 

 of 3 scales. Flowers white or yellowish, or reddish-purple 

 with age. Calyx lobes very unequal. Sandy hillsides. June- 

 July. 



2. E. heracleoides Nutt. A tomentose perennial. Leaves 

 spatulate-oblanceolate; tomentose but green above, white-woolly 

 below; margins more or less undulate. Inflorescence umbellate, 

 on a whorled and leafy-bracted peduncle. Flowers cream- 

 colored or yellowish; glabrous. Achenes not winged. Hillsides. 

 May-Sept. 



3. E. umbellatum Torr. Sulphur-flower. Tomentose peren- 

 nial herbs. Leaves spatulate-oblanceolate; smooth and shining 

 above, white-woolly below. Inflorescence umbellate, on a long, 

 naked (or rarely 1-bracted) peduncle. Flowers yellow, gla- 

 brous, usually turning reddish in fading. Achenes not winged. 

 E. umbelliferum Greene is a form with under surface of leaves 

 nearly glabrous when mature. E. umbellatum majus Benth. 

 (E. subalpinum Greene) has cream-colored instead of yellow 

 flowers, and is found at lower elevations than the type. Moun- 

 tain ridges, 5,000-9,000 ft. May-Sept. 



2. RUMEX. Sour-dock. 



Annual or perennial mostly coarse and homely herbs, with 

 grooved stems. Stipular sheaths conspicuous. Inflorescence 

 a, panicled raceme. Flowers dioecious, polygamous or perfect; 

 on jointed pedicels; not involucrate; whorled; small and green- 

 ish. Sepals 6, in 2 sets of 3;' the inner set veiny, sometimes with 

 a tubercle on back; enlarging in fruit, (and then called valves 



