EVENING-PRIMROSE FAMILY 597 



15. A. cinerea Rydb. Branched perennial; stem 3-4 dm. high, cinereous- 

 strigose when youngf leaves lanceolate to ovate-lanceolate, mostly subsessile, 

 3-5 cm. long, sinuate-dentate or denticulate, cinereous; tips of the calyx free 

 and rather long; petals 15-18 mm. long; pods 3-3.5 cm. long, 3 mm. thick, almost 

 straight. Dry soil: S.D.— w Neb.— Ida.— Colo. PlainSubmoni. Je-Jl. 



16. A. runcinata (Engelm.) Woot. & Standi. Perennial; stem much branched, 

 2^ dm. high, cinereous; leaves lanceolate to linear, canescent-strigose, 2-6 cm, 

 long, pinnatifid, with triangular-lanceolate, divergent lobes; tube of hypanthium 

 and calyx-lobes each 1.5-2 cm. long; free tips about 1 mm. long; petals 1.5-2 cm. 

 long; pod divergent, 3-4 cm. long, 2-3 mm. thick, often twisted. O. albicauhs 

 runcinata Engelm. Dry places: Tex. — Utah— Ariz. Son. Ap-S. 



17. A. latifolia Rydb. Perennial, whole plant strigose-canescent; stem 

 divaricately branched, 2-6 dm. high; leaves ovate, oblong or lanceolate, smuate- 

 dentate, 2-6 cm. long; tube of hypanthium and calyx-lobes about 2 cm. long; 

 free tips 1.2-2 mm. long; petals nearly 2 cm. long; capsule divaricate, usually 

 curved, 3 cm. long, 3 mm. thick. Sandy soil: Neb.— Kans.— Utah— Ida. Flam 

 — Mont, 



18. A. coronopifolia (T. & G.) Britton. Perennial, with a rootstock; 

 stem 1-3 dm. high, strigose; leaves 1-6 cm. long, pinnatifid, with hnear divisions, 

 or the basal ones spatulate and merely dentate; tube of hypanthimn 1-2 cm. 

 long, strigose; calyx-lobes 1.5-2 cm. long; free tips less than 1 mm. long; petals 

 1-1.5 cm. long; capsule oblong, 1-1.5 cm. long, 4 mm. thick. 0. coronopifolia 

 T. & G. Prairies and plains: S.D.— Kans.— N.M.— Ariz.— Ida. Plain— Mont. 

 Je-Au. 



12. PACHYLOPHUS Spach. Rock Rose, Mountain PmMROSE. 



Acaulescent or short-stemmed perennials. Leaves mostly crowded, toothed, 

 lobed, or pinnatifid. Flowers axiUary, perfect, night-blooming. Hypanthium 

 much elongated beyond the ovary into a narrowly funnelform tube. Sepals 4, 

 elongate, reflexed. Petals white, turning pink, sho%vy. Stamens 8. Stigma 

 with 4 hnear lobes. Capsule lance-ovoid or ovoid-oblong, large, 4-angIed, with 

 more or less wav>'-crestcd angles, woody, tardily locuhcidal. Seeds many, m 1 

 or 2 rows in each cell. 



Plant glabrous, or nearly so. 1- ^- caespitosum. 



Plant hairy. 



Plant not canescent-strit^ose. , , , , . -.t. x i *. 



Leaves ij-rate-pinnatifid; apex and lobes rounded or obtuse : hairs with pustulate 

 r |;)ases ' '2. i^. JonnsoTii* 



Leaves sinuately lobed or toothed, acute; hairs not pustulate at the bases. ; 

 Hypanthium. calyx, and fruit glabrous, slightly strigose or with a few scattered 



long hairs. , ' , ^ _. « „ 



Tube of the hjTantliium 3-6 cm. long; pubescence short and usually ap- 

 pressed. 3. P. montanus, 



\ Tube of hji)anthium 6-12 mm. long. ^ . 



Plant acaulescent, cespitose; pod short, conic-ovoid, with very thick 



ridges '*• ■^- J^icicroglottis. 



Plant more or less caulescent; pod elongate, conic-ovoid, with low ridges. 



5. P. caulescens, 



Hj-pantliium, calyx, and fruit densely hirsute. 



Fruit subsessile, conic-ovoid, obtuse at the base. 



Plant acaulescent; ridges of the fruit sUghtly tuberculate. 



Hypantliium 8-12 cm. long; petals 3-4 cm. long. 6. P. hirsutus. 



Hvnantliium about 5 cm. long; petals about 2 cm. long. 



7. P. crinitus. 



Plant more or less caulescent; ridges of the fruit with lobed, more or 

 Jess foliaceous crests. * , 8. P. ^f^^^'u^. 



Fruit more or less stipitate. fusiform, tapering at both ends, with slightly 

 tul>erculate ridges; plant often more or less caulescent. 9. P. marginatus. 

 Plant densely canescent-strigose throughout. 10. P. canescens. 



1. P. caespitosus (Nutt;) Raim. Cespitose acaulescent perennial; leaves 

 with'winged t)etioles, 1-2 dm. long; blades oblanceolate, glabrous, sinuate-den- 

 tate with triangular teeth; tube of the hypanthium 5-10 cm. long, glabrous; 

 petals 3-4 cm. long; fruit lance-ovoid, 3 cm. long, with low rounded tubercles 

 on the angles. Oenothera caespitosa Nutt. P. glabra A. Nels., a depauperate 

 form Dry hUls: Sask.— Neb.— N.M.— Utah— Mont. Plain— Mont. Je-Au. 



f ^ 



