STANDEE Y TKEES AND SHRUBS OF MEXICO. 445 



5-lobed ; stamens 10 or 9 ; fruit indehiscent, 1 or few-seeded, usually included in 

 the calyx. 



Many herbaceous species of the genus occur in Mexico. The shrubby forms 

 are of scarcely any economic importance, and very few vernacular names are 

 recorded for them. An infusion of the leaves of some species is said to be em- 

 ployed in Ecuador as a remedy for indigestion. 

 A. Flowers pediceled, reflexed. 

 Calyx lobes longer than the tube. 

 Leaves and stem glabrous. 



Leaflets 17 to 37, less than 2 mm. long 1, P. filiciformis. 



Leaflets 5 or 7, 3 to 4 mm. long 2. P. berlandieri. 



Leaves and stem pubescent. 

 Calyx lobes filiform, plumose; flowers subtended by 1 to 3 prominent 



glands 3. P. sericocalyx. 



Calyx lobes lance-subulate, not plumose ; flowers not subtended by glands. 



Flowers 8 to 10 mm. long ; leaflets 15 to 29 4. P. calycosa. 



Flowers about 6 mm. long ; leaflets 9 to 17 5. P. orcuttii. 



Calyx lobes shorter than the tube or barely equaling it. 

 Leaves simple. 



Leaves, at least the lower ones, obovate or spatulate, toothed ; ovules 4 to 



6; calyx with a single gland in each interval 6. P. spinosa. 



Leaves narrowly linear ; ovules 2 ; glands 2 or more in each interval. 

 Branches glabrate, bright green ; leaves sparsely pubescent. 



7. P. schottii. 

 Branches densely gray-strigose. becoming yellowish ; leaves densely 



strigose 8. P. puberula. 



Leaves pinnate. 



Calyx hairy outside. 

 Leaves conspicuously hairy. 



Pubescence of the stem and peduncles spreading 9. P. g'oldmani. 



Pubescence of the stem and peduncles appressed. 



Calyx canescent throughout 10. P. parryi. 



Calyx glabrous below, canescent-hirsute above 11. P. maritima. 



Leaves glabrous or nearly so. 



Stems decumbent, pilose 12. P. procumbens. 



Stems erect, glabrous or sparsely strigose. 



Leaflets punct.ite above 81. P. hospes. 



Leaflets not punctate above. 



Leaflets 2 mm. long, retuse; calyx 2.5 mm. long 13. P. palmeri. 



Leaflets 7 to 10 mm. long, obtuse ; calyx 3 to 3.5 mm. long. 



14. P. neglecta. 

 Calyx glabrous outside. 

 Calyx hairy inside. 



Calyx strongly angled, not conspicuously glandular. 

 Leaves pubescent. 



Leaflets sparsely pilose; stem glabrous 15. P. anthonyi. 



Leaflets densely strigose; stem canescent 11. P. maritima. 



Leaves glabrous. 



Leaflets linear 16. P. radicans. 



Leaflets oblong or oval. 



Branches strigose 22. P. oculata. 



Branches glabrous. 



Upper 4 calyx lobes acute 17. P. varieg'ata. 



Upper 4 calyx lobes obtuse 18, P. divaricata. 



