strongly keeled and subtending the accrescent ovary, the other 2 erect, oblong- 

 obovate and plane; stamens 6, the filaments shorter than the anthers; pistil 2- 

 carpellary, the ovary strongly compressed; styles 2, short; stigma dilated, fimbriate; 

 fruit lenticular, prominently winged, much compressed, oval, 4-6 mm. wide. 



In seepage at timberline, commonly about boulders and on open wettish rocky- 

 gravelly slopes, in N. M. (Colfax, Taos and Rio Arriba cos.) and Ariz. (Coconino 

 Co.), June-Sept.; Greenl. to Alas., s. in mts. to N. H., N.M., Ariz, and Calif.; 

 Euras. 



3. Rumex L. Dock 



Annual or perennial herbs; leaves alternate, flat, undulate or crisped, narrowed 

 to cordate or auricled at base; ocreae thin, brittle, often brownish; flowers greenish, 

 on pedicels that are jointed to and terminate short peduncles, in distant or approxi- 

 mate whorls disposed usually in elongate panicles; perianth lobes 6, the inner 3 

 (valves) usually developing entire, toothed or spiny wings one or each of which 

 usually bears a tuberclelike grain, in fruit the valves greatly increasing in size 

 compared to their size at anthesis and erect and usually loosely coherent to the 

 achene; the 3 outer sepals much smaller than the inner ones, usually lanceolate or 

 subulate and slightly spreading or arcuate; stamens 6; ovary sessile; styles 3, the 

 stigmas peltate and tufted; achene trigonous. 



About 200 species widespread in the world. The sap usually is quite acid and 

 in some species has been used in tanning leather, especially the "canaigre," 

 R. hymenosepalus. The leaves of some species are cooked as greens. 



Additional species in this wide-ranging, weedy genus should be found in our 

 region. They are not an easy lot! 



1. Flowers unisexual or polygamous; leaves usually hastately lobed (2) 



1. Flowers usually bisexual; leaves never hastately lobed (3) 



2(1). Valves (inner sepals) not larger than the achene; plant spreading by long 

 slender rootstocks 1. R. Acetosella. 



2. Valves distinctly overtopping the achene; plants without slender rootstocks 



2. R. hastatulus. 



3(1). Stems erect, ascending or procumbent; axillary shoots present below in- 

 florescence or rarely absent (doubtful cases should be keyed under 

 both alternatives) (4) 



3. Stems usually erect; axillary shoots absent (9) 



4(3). Pedicels straight, conspicuously turned downward, (2) 2.5 to 5 times as 

 long as the valves 3. R. verticillatus. 



4. Pedicels curved, at most twice as long as the valves (5) 



5(4). Valves 7-8 mm. long, 8-12 mm. broad 4. R. spiralis. 



5. Valves much smaller (6) 



6(5). Leaves ovate-lanceolate to elliptic-lanceolate, broadest below the middle; 

 valves more than 4.5 mm. long 5. R. altissimus. 



6. Leaves usually narrower, lanceolate or linear-lanceolate, if exceptionally broad 



then the fruit much smaller (7) 



7(6). Valves without grains 6. R. calif ornicus. 



7. One valve or all bearing grains (8) 



8(7). Leaves small and thickish, in the dry state olive-green, often undulate- 

 crisped, somewhat obtuse, with strongly prominent nerves beneath; 

 panicles interrupted, most whorls remote 7. R. chrysocarpus. 



8. Leaves larger, rather thin, in the dry state pale-green, acute; nerves scarcely 



prominent; fruiting panicle not interrupted or only in the lower part 

 8. R. mexicanus. 



797 



