KEY TO THE SPECIES 19 



pedicels, the outer sepals broader than the inner. Sandy slopes and plains ; 

 common. 



■I- -i- Perennial. 



7. Eriogonum ovalifollum Nutt. (Oval-leaved Ebiooonum). Cespitose ; 

 leaves from the crowns of the much-branched caudex, from orbicular to ovate ; 

 bracts very small ; involucres in a single close head ; flowers yellow. This species 

 is abundant in but few localities, but the following variety is very generally dis- 

 tributed. 



Var. purpureum (Nutt.) Aven Nelson. Size and habit of the species ; the 

 flowers varying from white through pink to purple. Dry gravelly plains. 



2. RUMEX (Dock) 



Coarse herbs often with large leaves, clusters of small mostly greenish flowers, 

 calyx of 6 sepals (3 outer spreading in fruit, 3 inner larger and somewhat colored, 

 enlarged after flowering, veiny, and closing over the nut-like fruit), 6 stamens, and 

 3 styles. 



* Wings much enlarged, without tubercles. 



1. Rumex venosus Pursh (Veined Dock). Stems stout, erect, 15-30 cm. 

 high, from running rootstocks ; leaves large, somewhat leathery, ovate to lanceo- 

 late, on short petioles ; panicle short, dense in fruit ; pedicels jointed at middle ; 

 the 3 inner sepals much enlarged in fruit, with conspicuous veined wings, a deep 

 sinus at the base, from reddish to a deep maroon-red, without grain-like tubercles 

 or callosities ; achene with smooth, shining concave faces. 



* Wings rather small, with tubercles. 



2. Rumex salicifolius Weinm. (Willow-leaved Dock). Stems clustered, 

 erect or spreading, 3-6 dm. high ; leaves lanceolate or narrower, tapering to both 

 ends, petioled ; racemes erect or spreading ; pedicels jointed near the base ; 

 wings each bearing an ovoid tubercle on the back ; achene acuminate, with con- 

 cave faces. 



3. POLYGONUM (Knotwbed. Smartvceed) 



Herbs with conspicuous stipules sheathing the prominent joints of the stem, 

 small flowers, a 5-parted often petal-like calyx, 4-9 stamens, 2 or 3 styles, and a 

 triangular or lens-shaped achene. 



1. Polygonum aviculare L. (Doorweed). Slender and smooth, mostly 

 prostrate or ascending, leafy throughout ; leaves oblong to lanceolate, acutish ; 

 sheaths 2-lobed or lacerate ; flowers in axillary clusters or in spikes with leafy 

 bracts ; sepals very small, with green and pinkish margins ; stamens 8 (rarely 5) ; 

 styles 3 ; nut dull and minutely granular. Yards and waste places. 



2. Polygonum bistortoides Pursh (Mountain Smartweed). Stems 3-5 

 dm. high, slender ; leaves mostly basal, oblong to linear, the cauline much 

 reduced ; flowers in a dense oblong spike terminating the scapose stem or pedun- 

 cle, white or rose-colored ; stamens and styles exserted ; achene smooth and shin- 

 ing. Frequent in grassy mountain valleys and parks. 



