26 SPRING FLORA OF MANHATTAN. 



PARTHENOCISSUS, Planch. 



Calyx shortly -5 toothed. Petals expandingr. Leaves pal mately com- 

 pound. 



P. 7HJ>i,7we/oKrt, (L.) Planch Leaflets .5, clinging to rough supports 

 by disk-like terminations. Woods, common. The older parts provided 

 with aerial rootlets. 



P. vitacea, (Knerr) Hitchc. Differs from the above in having no 

 aerial rootlets; the canes smooth, and lighter colored; the tendrils dichot- 

 omous like the grape, and usually without disks; the inflorescence dichoto- 

 mous rather than pinnate as in the former; flowering about two weeks 

 earlier; the fruit maturing earlier and considerably larger. Woods, 

 infrequent. 



43. MALVACEAE. 



Sepals 5, more or less united, often provided with a whorl of bractlets 

 outside. Petals 5. Stamens numerous, united in a column. Pistils 

 several, united in a ring. Leaves alternate, with stipules. Ours herbs. 



MALVA, L. 



Involucel of 3 bractlets. Carpels rounded, beakless. 



M. rotundifolia, L. Stems spreading. Leaves on long petioles, 

 round-cordate, crenate. Petals whitish. Waste places, infrequent. 

 CALLIRHOE, Nutt. 



Involucel 3-leaved or none. Carpels beaked. 



C. alcceoides, (Michx.) Gray. Stem erect. Involucel none. Flowers 

 pink or white. Prairie, not common. 



C. involucrata, (Nutt.) Gray. Stem spreading. Involucel .3-leaved. 

 Flowers deep red. Prairies, common. 



44. VIOLACEAE. 



Sepals .5. Petals 5, irregular. Stamens 5. Pistil one, 1-celled, with 

 3 parietal placentae. Herbs. 



VIOLA, L. 



Sepals eared at base. The lower petal spurred and two of the 

 stamens sending appendages into the spur. Ours with blue flowers. 



F. obliqua., Ilill. Stemless. Leaves cordate, crenate. Woods, 

 common. 



r. pedatifida, Don. Stemless. Leaves palmately cleft into narrow 

 lobes. Prairie, frequent. 



V. tenella, Muhl. Stem low, with oval leaves and large pinnatifld 

 stipules. Flowers small, light blue. Grassy places, frequent. 

 CALCEOLARIA, Loefl. 



Sepals not eared. Leafy perennials witli small axillary flowers. 



C. vertidllata, (Ort.) Kuntze. Leaves linear. Flowers white. 

 Prairie, infrequent. 



45. OENOTHERACEAE. 



Parts of flower usually in four's. Pistil one, adherent to calyx tube, 

 4-celled. Herbs. 



CENOTHERA, L. 



Calyx tube prolonged beyond the ovary, lobes 4. Petals 4. Stamens S. 



