146 Order ROSALES 
county; Franklin; Long Pine; Niobrara; Scotts Bluff county; Valen- 
tne. it 
21. Petalostemum (Kuhnistera). 546. 
Densely villous or silky-pubescent all over; leaflets 9-17. 1. P. villosum. 
Glabrous or nearly so; leaflets 3-9. 
Flowers purple; leaflets 3-5, 2. P. purpureum. 
Flowers white; leaflets 3-9. 
Calyx densely silky-villose. 3. P. compactum. 
Calyx glabrous or nearly so. 
Leaflets lanceolate or oblong 15-25 mm. long. 4. P. candidum. 
Leaflets linear or nearly so, mostly less than 20 mm. long, 
3-4 mm. wide. 5. P. oligophyllum. 
1. Petalostemum villcsum Nutt. Hairy Prairie-clover. 
In dry soil, common in the sand-hills. Foster; Kearney; Mullen; 
Pishelville; Royal; Thedford; Valentine; Valley Junction. 
2. Petalostemum purpureum (Vent.) Rydb. Purple Prairie-clover. 
Common in prairies throughout the state. Brown county; Danne- 
brog; Deuel county; Kearney; Lincoln; Plummer Ford; Sioux county; 
Weigand. 
3. Petalostemum compactum (Spreng.) Swezey. 
Rare in the western part of the state. Scotts Bluff county. 
4. Petalostemum candidum (Willd.) Michx. White Prairie-clover. 
Common in rich soil in the eastern and central parts of the state. 
Crawford; Brown county; Fairbury; Haigler; Kearney; Lincoln; 
Niobrara. 
5. Petalostemum oligophyllum Torr. 
Common in sandy places in the central and western parts of the 
state. Ashton; Callaway; Sioux county. 
22. Apios (Glycine). 569. 
1. Apics tuberosa Moench. Ground-nut. 
Apios apios (L.) MacM. 
Common in rich soil in the eastern part of the state and extending 
along streams farther west. Keyapaha county; Peru; Platte River; 
Plummer Ford; Valentine. 
23. Strophostyles. 571. 
Leaflets broadly ovate, often lobed; pods slightly pubescent. 
1. S. helvela. 
Leaflets lanceolate, or linear oblong, entire; pods very pubescent. 
2. S. pauciflora. 
1. Strophostyles helvola (L.) Britton. Trailing Wild Bean. 
In sandy soil in the eastern part of the state. Guide Rock; Lincoln; 
Neligh; Paddock; Pauline; Red Cloud; Seward. 
2. Strophostyles pauciflora (Benth.) S. Wats. Small Wild Bean. 
In sandy soil along streams throughout the state. Atkinson; Big 
Sandy creek; Dismal River; Elgin; Hastings; Kearney; Lincoln; 
Nelson; Wahoo. 
24. Falcata. 569. 
Bracts rhombic-oval, shorter than the pedicels; calyx of the perfect 
flowers 3-4 mm. long. 1. F. comosa. 
