LOASA FAMILY 571 



Petal-like staminodia none; petals 5, yellow; a few of the outer filaments sUghtly dilated. 

 Stem glabrous or nearly so, white and shining ; upper stem-leaves neither with a broad 



base, nor long-acuminate. 17. N. laevicaulis. 



Stem pubescent throughout, straw-colored, rather dull; upper stem-leaves long- 

 aciuninate and with a broad base. 

 Petals 5-7 cm. long; leaves coarsely hirsute-scabrous. 18. N. acuminata. 



Petals 2.5-3 cm. long; leaves finely scabrous-puberulent. 19. N. varviflora. 



1. N. lutea Greene. Stout biennial, 6-9 dm. high, with a fusiform fleshy 

 root; lower leaves sinuate-pinnatifid, the upper sinuate-dentate; petals elliptic, 

 short-clawed, acute; petaloid staminodia about three-fourths as long; capsule 

 thick-walled. Mentzelia lutea Greene. Alkaline soil: Colo. Submont. S. 



2. N. multicaulis Osterhout. Much branched perennial; stems many, 

 white, shining, 2-4 dm. high; lower leaves pinnatifid, with oblong divisions; 

 flowers opening at sundo'^vn; sepals lanceolate, acuminate, 1 cm. long; petals 

 spatulate, 17-20 mm. long; petaloid staminodia about half as large; capsule 

 fully 1 cm. long; seeds smooth, margined. T. multicaulis Osterhout. Dry soil: 

 Colo. Suhmont. Je-Jl. 



3. N. multiflora (Nutt.) Greene. Corymbosely branched perennial or 

 biennial; stems bright white and shining, scabrous-puberulent, 3-6 dm. high; 

 petals spatulate, 12-20 mm. long; petaloid staminodia slightly smaller; capsule 

 15-20 mm. long, acute at the base. Bartonia multiflora Nutt. Dry plains: w 

 Tex. — Colo.— Ariz. — Utah — Mex. Submont. — Mont. Ap-S. 



4. N. lobata Rydb. Perennial, with a thick root; stems strict, white and 

 shining, 3-4 dm. high; leaves 5-S cm. long; sepals lanceolate, acuminate, 8-10 mm. 

 long; flowers diurnal; petals spatulate, 12-18 mm. long; petaloid staminodia 

 similar and almost as large; capsule 15 mm. long. Sandy soil: s Utah. L. Son. 

 Jl. 



5. N. pterosperma (Eastwood) Greene. Biennial; stem white, 1-3 dm. 

 high, divaricately branched; lower leaves spatulate, 2.5-3 cm. long, sinuately 

 dentate, with broad, usually obtuse teeth; petals oblanceolate, 1-1.5 cm. long; 

 petaloid staminodia similar; capsule about 1 cm. long. Sandy valleys: Colo. — 

 Utah. Son. Je-Jl. 



6. N. humilis (A. Gray) Rydb. Low branched perennial or biennial; stem 

 2-4 dm. high, scabrous-puberulent; leaves pinnatifid; petals oblanceolate, 8-10 

 mm. long, bright yellow; petaloid staminodia almost as large; capsule 7-10 mm. 

 long, rounded at the base. M. multiflora humilis A. Gray. Dry soil: w Tex. — 

 Colo.— N.M. Son. 



7. N. Integra (M. E. Jones) Rydb. Rather simple biennial; stem puberu- 

 lent, 2-3 dm. high; lower leaves 4-5 cm. long; sepals lanceolate, 7-8 mm. long; 

 petals oblanceolate, 15-18 mm. long; staminodia similar, sUghtly smaUer; cap- 

 sule 12-15 mm. long, acute at the base. M. multiflora integra M. E. Jones. 

 Sandy or clayey soil: Utah. Son. My-S. 



8. N. pumila (Nutt.) Greene. Low biennial; stem scabrous-puberulent, 

 2-3 dm. high; leaves oblanceolate, 4-8 cm. long, sinuately pinnatifid; petals 

 oblanceolate, acute, 10-12 mm. long; staminodia similar, but somewhat smaller; 

 capsule fully 1 cm. long, acute at the base. M. pumila Nutt. Barren hills and 

 sandy flats: Wyo. — Colo. — Utah. Submont. Je. 



9. N. densa Greene. Low perennial, with thick root and several stems; 

 stems white, puberulent, 2-4 dm. high, branched; leaves oblanceolate, 3-6 cm. 

 long, deeply pinnatifid; sepals lanceolate, acuminate, nearly 1 cm. long; petals 

 about 15 mm. long; staminodia similar, scarcely smaller; capsule about 15 mm. 

 long. Hillsides, caiions, and dry table-lands: Colo. — Utah — N.M. Son. — Mont. 

 Je-Au. 



10. N. laciniata (Rydb.) Woot. & Standi. Biennial or short-lived peren- 

 nial; stems 3-4 dm. high, white, puberulent; leaves 5-10 cm. long; petals 15-20 

 mm. long, short-clawed, oblanceolate; staminodia similar; capsule 15-18 mm. 

 long. Touteria laciniata Rydb. Hillsides: Colo. Submont. Je-Jl. 



11. N. speciosa (Osterhout) Greene. Stout perennial; stem whitish, puberu- 

 lent, corymbosely branched, 3-8 dm. high; leaves linear or oblong-lanceolate, 10- 



