600 ONAGRACEAE 



Throat of the hypanthium dark purple within, 5-6 mm. broad at the mouth. 



1. M. melanoglottis 

 Throat of the h>-panthium orange within, sometimes with a darker ring at the base of 

 the stamens, 3-4 mm. broad at the mouth. 2. M. serrulate. 



1. M. melanoglottis Rydb. Perennial, shrubby and branched at the 

 base; stems 2.5-4 dm. high, the upper portion as well as the leaves grayish 

 strigose; leaf-blades spatulate to almost linear, 2.5-6 cm. long, shallowly serrate; 

 petals 10-12 mm. long; capsule straight, 2 cm. long, copiously pubescent. Dry 

 soil: Tex. — Colo. Plain. 



2. M. serrulata (Nutt.) Walp. Perennial, woody at the base; stem 1-5 

 dm. high, branched and leafy, more or less canescent; leaf -blades spatulate to 

 hnear-oblong or linear, 2-5 cm. long, serrate, canescent-strigose; petals obovate, 

 8-12 mm. long, crenulate; capsule 1.5-2 cm. long. Oenothera serrulata Nutt. 

 Dry soil, plains and hills: Man. — Mo. — Tex. — Ariz. — Alta. Plain — Submont. 

 Je-Au. 



17. TARAXIA Nutt. 



Acaulescent perennial herbs, with a short caudex. Leaves crowded at the 

 base, pinnatifid or entire. Flowers perfect, regular, axillary. Hypanthium 

 prolonged beyond the ovary into a slender cyHndric tube, marcescent. Petals 

 4, yellow or white. Stamens 8. Stigma capitate, entire or 4-toothed. Capsule 

 sessile, oblong, 4-winged. Seeds in a double row in each cell of the ovary. 



Leaves entire or merely toothed. 1. T. subacaulis. 

 Leaves pinnatifid. 



Hypant)iium 2-5 cm. long; petals about 5 mm. long. 2. T. breriflora. 



Hypanthium 6-10 cm. long; petals 10-14 mm. long. .3. T. longiflora. 



1. T. subacaulis (Pursh) Rydb. Acaulescent perennial; leaves oblance- 

 olate or lanceolate, 7-15 cm. long, entire or repand, glabrous; tube of hypanthium 

 3-4.5 cm. long, slender; petals i)ale yellow, 8-12 mm. long; ca])sule ovate-ellip- 

 soid, 1.5-2 cm. long. Oenothera heterantha Nutt. Plains and valleys: Mont. — • 

 Colo. — Calif. Subnwnt. Je-Au. 



2. T. breviflora Nutt. Acaulescent perennial; leaves deeply pinnatifid, 

 5-12 cm. long, minutely pubescent; sepals and yellow petals about 5 mm. long; 

 capsule about 1.5 cm. long, lance-ovoid, tuberculate. 0. hrcviflora T. & G. 

 Plains and valleys: Alta. — Wyo. — Utah — B.C. Plain — Submont. Je-Au. 



3. T. longiflora Nutt. Acaixlescent perennial; leaves narrowly oblance- 

 olate in outline, sinuately pinnatifid to near the midrib, 8-15 cm. long, sparsely 

 strigose; sepals narrowly lance-oblong, 8 mm. long; petals eraarginate or rounded, 

 yellow; capsule lance-ovoid, round-ridged. 0. Nuttallii T. & G. T. tikurana 

 A. Nels. Meadows: Calif. — Ida. — Wash. Submont. Je-Au. 



18. SPHAEROSTIGMA F. & M. 



Annual or perennial caulescent herbs. Leaves alternate, entire or pinnatifid. 

 Flowers small or minute, in bracted or leafy spikes. Hypanthium produced 

 bej'ond the ovary into an obconic short tube. Sepals 4. Petals 4, yellow, white, 

 or pink, entire or emarginate. Stamens 8, slightly unequal. Stigma capitate, 

 entire. Capsule sessile, linear, terete or 4-angled, often more or less twisted and 

 curved, 4-celled. Seeds linear-oblong, smooth. 



Corolla yellow, turning reddish or greenish. 



Capsule fu.siform. 1. S. andimtm. 



Capsule Unear. 



Leaves narrowly linear. 



Plant glabrous, or nearly so. 



Pods straight, erect. 4. S. parvulum. 



Pods curved, often reflexed. 5. A', flexuosum. 



Plant more or li^ss pubescent, at least when young. 



Plant strigillose; leaves usually dentate. 6. S. slrigulosum. 



Plant hirsutulous below, often glandular above; leaves usually entire, 

 linear. 8. S. pubens. 



Leaves oval, lanceolate, or oblong. 

 Petals 1-2 mm long. 



Plant dwarf, only a few centimeters high, strigillose; capsule about 2 cm. 

 long. 9. S. 7ninus. 



