20 SPRING FLORA OF MANHATTAN. 



Palmate; flowers white Rnbus 



Pinnate; flowers pink Bosa 



2. Herbs. 



Flowers white Fragaria 



Flowers yellow Potentilla 



PRUNUS, L. 

 P. Aynericana, Marsh. Flowers appearing before the leaves Fruit 

 ovoid; stone flat. Leaves ovate, doubly serrate, veiny. Many of the 

 branches thorn-like at apex. A small tree. Thickets, common. 



P, anqustifolia, Marsh. Resembles the foregoing, but leaves narrower 

 and tending to be partially folded together, finely and evenly glandular- 

 serrate. Fruit globular; stone more turgid. Sand hills along the river. 

 A shrub. 



CERASUS, L. 

 C. Virginiana, (L.) Loisel. Flowers appearing just after the leaves. 

 Fruit and stone globular. Leaves obovate, thin. A tall shrub, not 

 thorny. Woods, not common. 



RUBUS, L. 

 Pistils numerous, becoming small drupelets in fruit. Somewhat 

 woody plants with prickly bark. 



B. occidentalis. L. Stems upright or declining, red, glaucous. 

 Leaflets 3, white-downy beneath. Petals shorter than sepals. Thickets 

 and fence corners, frequent. 



B. villosus. Ait. Stems upright or decUning, brown, furrowed. 

 Leaflets 3 5, the terminal 1-3 stalked, glandular pubescent. Petals longer 

 than sepals. Roadsides, rather uncommon. 



B. Canadensis, L. Stems trailing. Leaflets usually 3, thin and 

 nearly smooth. Otherwise resembles the preceding. Woods about St. 

 George. 



FRAG.ARIA, L. 

 Calyx with 5 bractlets alternating with the lobes. Pistils numerous 

 becommg achenes. The receptacle becoming in fruit enlarged and 

 pulpy. Jjeaves radical, trifoliate. Flowers cymose on scapes. Spread- 

 ing by runners. 



F. Virginiana, Mill. Low prairie, common. 



POTENTILLA, L. 



As in Fragaria but receptacle not becoming pulpy in fruit. Ours 

 with leafy stem. 



P. Monsijeliensis, L. Stem erect, 2-5 dm. Leaflets 3. Sandy soil, 

 infrequent. 



P. pentandra, Engelm. More slender, flowers smaller and the lower 

 leaves with the lateral leaflets parted nearly to the base, thus appearing 

 5-foliate. Sandy soil, rare. 



ROSA, L. 



Calyx tube ovoid, contracted at summit where are borne the petals 

 and stamens, becoming fleshy in fruit. The several pistils at tlie bottom 

 of the tube becoming bony, hairy achenes. 



