368 POLYGONACEAE 



3. Briogonum longif olium Nutt. Perennial by a thick rootst ock, pubescent. Stems 

 6-13 dm. tall, paniculaiely or corymbosely branched above, finely grooved : leaves mostly 

 at the base of the stem ; blades narrowly oblong or linear-oblong. 5-22 cm. long, silky- 

 strigose above, tomentose beneath, obtuse or acutish, the upper ones sessile, the lower ones 

 attenuate into winged petioles with dilated sheathing bases : peduncles mostly less than 1 

 cm. long : involucres turbinate-campanulate, 4-5 mm. high : calyx herbaceous, 4-5 mm. 

 long, densely silky with silvery hairs : sepals lanceolate or oblong-lanceolate : achene 3- 

 angled. 



In sandy soil, southern Missouri to the Indian Territory and Texas. Spring to fall. 



4. Eiiogoimm dnnuum Nutt. Annual, floccose-tomentose with white hairs. Stems 

 erect, 3-9 dm. tall : leaf -blades narrowly oblong or oblanceolate, 2-7 cm. long, acute or 

 obtuse, flat or slightly revolute, or crisped, attenuate into short petioles : peduncles shorter 

 than the stems or almost wanting, topped by a dichotomous compound cyme : involucres 

 turbinate or turbinate-campanulate, 2-3 mm. high, very short-stalked, densely white- 

 tomentose ; lobes 5, obtuse : calyx white or pink, 1-2 mm. long, glabrous, the outer 

 sepals obovate, the inner narrower, all truncate or retuse at the apex, sometimes fiddle- 

 shaped : achenes 3-angled, 1.5 mm. long, with a globular base and a beak of equal length, 

 the angles smooth. 



In dry places, Nebraska to Texas, New Mexico and Chihuahua. Summer and fall. 



5. Eriogonum multiflorum Benth. Annual, woolly-tomentose with white hairs. 

 Stems erect 3-10 dm. tall, leafy below, strict : leaf -blades lanceolate or oblong-lanceolate, 

 2-7 cm. long, acute or obtuse, undulate and often crisped, revolute, sessile and somewhat 

 auricled : peduncles 2-30 cm. long, each topped by a trichotomous cyme : involucres 

 turbinate-campanulate, about 2 mm. high, shorter than their stalks ; lobes 5, triangular : 

 calyx white, 2-3 mm. long, glabrous : sepals very unequal, the outer suborbicular, retuse 

 or notched at the apex, cordate at the base, the inner linear, shorter than the outer : achenes 

 3-angled, about 3 mm. long, subglobose below, each narrowed into an acute beak. 



In dry soil, Arkansas to Louisiana and Texas. Summer and fall. 



6. Eriogonum tenellum Nutt. Perennial, usually scapose. Stems sometimes de- 

 veloped, 1-3 dm. long, leafy : leaves usually basal ; blades ovate or suborbicular, 0.5-1.5 

 cm. in diameter, obtuse or acutish, gradually or abruptly narrowed at the base, densely 

 and softly tomentose on both surfaces ; petioles longer than the blades or shorter : scapes 

 often wand-like, 1-4 dm. tall, rather sparingly branched : involucres turbinate-campanu- 

 late, 3-4 mm. high, on more or less elongated stalks ; lobes 5, broad, often acutish : calyx 

 white or pink, at length about 3 mm. long, glabrous, the outer sepals obovate or sub- 

 orbicular, retuse or notched at the apex, more or less spreading, the inner sepals linear- 

 oblong, erect, shorter than the outer : filaments slightly villous at the base : achenes 3- 

 angled, 2.5 mm. long, globose at the base, each short-beaked. 



In dry places, Colorado to Texas, New Mexico and Chihuahua. Summer and fall. 



2. RUMEX L. 



Annual or usually perennial, caulescent herbs, with large roots. Leaves alternate : 

 blades entire, flat, undulate or crisped, narrowed, or cordate or auricled at the base : ocreae 

 thin, brittle. Flowers green, perfect, polygamo-monoecious or dioecious on pedicels which 

 are jointed to and terminate short peduncles, in distant or contiguous whorls disposed in 

 panicles. Sepals 6, the 3 inner usually developing entire toothed or spiny wings one or 

 each of which usually bear a callosity. Stamens 6. Ovary sessile : styles 3 : stigmas peltate, 

 tufted. Achene 3-angled, usually invested by the accrescent calyx, its angles more or 

 less margined. DOCK. SORREL. 



Flowers dioecious : some or all of the leaves with hastate blades : plants sour. 



Inner sepals not developing wings : achenes granular. 1. R. Acetosella. 



Inner sepals developing wings : achenes smooth. 2. E. hastatulus. 



Flowers polygamo-monoecious : none of the leaves with hastate blades : plant 



not sour. 

 Sepal-wings entire, undulate or shallpwly toothed. 



Leaves flat or the margins sometimes slightly crisped, usually pale, the 



lower ones mostly narrow. 

 Pedicels together with the peduncles, or at least some in a cluster, 



longer than the wings. 



Leaf-blades about twice as long as broad. 3. R. fascicularis. 



Leaf- blades several times longer than broad. 



Pedicels together with the peduncles several times longer than 



the wings. 4. It. verticillatus. 



Pedicels together with the peduncles slightly longer than the 



wings. 5. R. salicifolius. 



