FAMILIES OF PLANTS 77 
that have been identified in the park may be distinguished by means 
of the following key: 
1. Leaflets 3. 2. 
1. Leaflets more than B. 4. 
2. Stamens more than 10. Potentilla monspeliensis. 
2. Stamens 10 or fewer. 3. 
3. Sepals longer than the bracts. Potentilla biennis. 
3. Sepals and bracts about equal. Potentilla leucocarpa. 
4. Leaves palmately compound. 5. 
4. Leaves pinnately compound. 10. 
5. Leaves white-woolly beneath. Potentilla gracilis. 
5. Leaves not white-woolly beneath. 6. 
6. Petioles bearing an extra pair of small leaflets. Potentilla subjuga. 
6. Petioles without an extra pair of small leaflets. 7. 
7. Leaflets toothed or cleft more than halfway to the midrib. Potentilla 
pectinisecta. 
7. Leaflets toothed or cleft halfway to the midrib or less. 8. 
8. Plants less than a foot high. Potentilla glaucophylla. 
8. Plants a foot or more high. 9. 
9. Plants densely silky at least below. Potentilla mridescens. 
9. Plants somewhat hairy but not densely silky. Potentilla nuttallii. 
10. Leaflets pinnately divided. 11. 
10. Leaflets toothed but not divided. 14. 
11. Leaflets divided halfway to the midrib or less. 12. 
11. Leaflets divided nearly to the midrib. 13. 
12. Leaflets 5 to 7. Potentilla diversifolia. 
12. Leaflets 7 to 15. Potentilla pennsylvaniea. 
13. Leaflets 5 to 7. Potentilla rubricaulis. 
13. Leaflets 7 to 15. Potentilla monidensis. 
13. Leaflets more than 15. Potentilla pmnatisecta. 
14. Plants 8 to 16 inches high. Potentilla hippiana. 
14. Plants less than 8 inches high. Potentilla Wyoming ensis. 
Potentilla qmnquefolia , which is much like P. gracilis , and P. 
macounii have been reported as found in the park. 
Geum strictum is a perennial herb with mostly basal, pinnate 
leaves and yellow flowers on short stalks. The fruits are akenes, 
and the styles which remain on the fruits are hooked, and thus 
enable the fruits to cling to the fur of animals or to clothing. 
Geum macroyhyllum has also been reported in the park. 
Prickly rose ( Rosa sayi). —The wild rose is easily recognized 
although the different species are sometimes quite difficult to dis¬ 
tinguish. This species has stems that are 1 to 3 feet high and 
thickly covered with prickles. The leaves have 3 to 7 leaflets which 
are doubly toothed. 
Fendler rose ( Rosa fendleri) is a larger plant, often becoming 5 to 7 
feet high, and the leaves have 5 to 7 leaflets which are simply toothed. 
The flowers are rather small. 
785717°—48-6 
