1016 CONTRIBUTIONS FROM THE NATIONAL HEKBAEIUM. 



Scale present below each dorsal petal. 

 Four ventral petals very obtuse at base and apex ; longer stamens 



equaling the calyx lobes 21. P. arnottiana. 



Four ventral petals cuneate at base, acute or obtuse at apex ; longer 

 stamens slightly exceeding the calyx lobes. 

 Leaves rounded or subcordate at base ; pedicels mostly 2 to 4 



mm. long 22. P. lobophora. 



Leaves acute or obtuse at base; pedicels mostly 5 to 10 mm. 



long 23. P. squamuligera. 



Dorsal lobe of the calyx not produced or, if so, the calyx scarlet. 



Calyx slender or very slender, the dorsal lobe usually broad but 

 shorter than the others, the mouth of the calyx oblique. 



Petals 6, subequal 24. P. aequipetala. 



Petals 2, or 6 but very unequal. 



Stamens 9 ; ovules 12 to 23 ; spur of calyx strongly incurved. 



25. P. bustamanta. 

 Stamens 11 ; ovules 3 to 11 ; spur obsolete or, if evident, never 

 incurved. 



Flowers solitary, not racemose 26. P. appendiculata. 



Flowers in evident terminal racemes. 



Calyx spurred at base 27. P. roseana. 



Calyx not spurred, merely gibbous at base. 

 Calyx glabrous within at base. 

 I Leaves setose-hirsute on the upper surface. 



28. P. megalophylla. 

 Leaves merely scaberulous on the upper surface. 



29. P. cristata. 

 Calyx hairy within at base. 

 Appendages of calyx shorter than the lobes ; calyx 



hirtellous 30. P. grfeciliflora. 



Appendages longer than the lobes; calyx minutely 



strigillose 81. P. boissieriana. 



Calyx thick and stout, convex dorsally, the lobes usually very short 

 or none. 

 Ovules 48 to 100. 



Petals included 32. P. micropetala. 



Petals, at least the 2 dorsal ones, exserted, nearly half as long as 



the calyx 33. P. heteropetala. 



Ovules 4 to 26. 

 Appendages of the calyx longer than the lobee, bulbous-ciliate at 

 base. 



Ovules 8; stems not hirsute 34. P. schumannii. 



Ovules 4; stems hirsute 35. P. bracteolosa. 



Appendages obsolete or shorter than the lobes or, if longer, never 

 bulbous-ciliate. 



Calyx lobes eciliate 36. P. baillonis. 



Calyx lobes ciliate. 



Petals evident, 2 mm. long or much longer. 

 Petals, at least the 4 ventral ones, very small. 



Petals very unequal, the 2 dorsal ones about half as 

 long as the calyx, the 4 ventral ones half as long and 



much narrower 37. P. heterophylla. 



Petals subequal, about 2 mm. long 38. P. joruUensis. 



