50 KEY TO THE SPECIES 



4. Viola cognata Greene (Mountain Meadow Violet). Glabrous, stemless ; 

 the leaves from renlform to round-cordate, crenate, very obtuse, 1-18 mm. broad, 

 long petioled ; peduncles usually longer than the leaves ; corollas large, light blue, 

 the petals villous at base. Wet mountain meadows. 



* * * Flowers variously colored ; leafy stemmed and with large foliar pin- 

 natifld stipules. 



5. Viola tricolor L. (Pansy). Stem angled and branched, leafy throughout; 

 leaves roundish or the upper oval and the lower heart-shaped, crenate or entire ; 

 flowers variable in color or variegated (yellow, white, violet-blue, purple, etc.). 

 Cultivated from Europe. 



XLI. LOASACE2E (LoASA Family) 



Herbs, rough with, hooked or stinging' hairs, no stipules, 

 regular ilowers, with 5 or 10 petals inserted with the stamens on 

 the throat of the adnate calyx-tube, many stamens, a 1-celled 

 capsule with parietal placentae. 



1. Mentzella. Flowers small, yellow; petals 5; seeds not winged. 



2. Hesperaster. Flowers large, white ; petals 10 ; seeds winged. 



1. MENTZELIA (Mentzelia) 



Brittle annuals with rough adhesive leaves ; obconic or terete, 5-lobed calyx 

 tube ; numerous filiform filaments, truncate ovary, and oblong or irregularly 

 angled seeds. 



1. Mentzelia albicaulis (Hook.) Dougl. (WnrrE-STEMMED Mentzelia). A 

 slender annual 1^' dm. high, branched ; stems light, becoming white and glisten- 

 ing ; leaves pinnatifid with narrow lobes ; petals spatulate or broader ; capsule 

 olavate ; the seeds irregularly angled, tuberculate. Frequent on dry loose banks 

 and slopes. 



8. Mentzelia Integrifolla (Wats.) Eydb. Quite similar, but the leaves from 

 entire to sinuate-toothed, from narrowly oblong to ovate ; seeds nearly cubical 

 and not tuberculate. 



2. HESPERASTER (Western Star) 



Stout, erect, more or les3 branched biennials or perennials, hooked pubescence, 

 pinnatifid leaves, large flowers with 10 petals or fewer, very numerous stamens and 

 winged seeds. 



1. Hesperaster decapetalus (Sims) T. D. A. C. (Showy Western Star). 

 Roughish pubescent, 3-7 dm. high ; leaves from ovate to lanceolate, sinuate-pin- 

 natifld ; flowers very large, 7-10 cm. across ; petals 10, white ; stamens exceedingly 

 numerous, all filiform ; capsule large, bracted at base ; the seeds winged. Flow- 

 ers opening at sunset. 



2. Hesperaster nuda (Pursh) T. D. A. C. (Bractless Evening Star). Some- 

 what similar but smaller, moderately branched ; the leaves lanceolate, with obtuse 

 segments ; flowers bracted at base, 4-6 cm. broad, the outer stamens sterile and 

 petal-like ; capsule nearly cylindric, 3-valved at summit ; the seeds winged. Fre- 

 quent on sterile denuded hills. 



