POMACEAE 107 



Stems nearly glabrous. 1. A. striata. 

 Stems pubescent to hirsute. 



Leaflets 5-11. 2. A. mollis. 



Leaflets 11-17. 3. A. parviflora. 



1. A. striata Michx. l°-3° high : leaflets 5-7, bearing few scattered 

 hairs, oblong-obovate, obtuse: flowers rather few. — Dry woods through- 

 out. Common, July-September. 



2. A. mollis (T. & G.) Britton. 2°-6° high, pubescent: leaflets 

 about 7, pubescent beneath, obovate : flowers numerous. — Common in 

 woods. July-September. 



3. A. parviflora Soland. 2°-6° high, densely hirsute below : leaflets 

 lanceolate to linear-lanceolate, glandular-pubescent : flowers very numer- 

 ous. Eather common in moist woods and prairies. July -September. 



9. ROSA L. 



Shrubs with prickly stems and alternate pinnate leaves. Calyx urn- 

 shaped, contracted at the mouth, becoming fleshy in the fruit, its limb 

 5-lobed. Petals 5, pinkish. Stamens numerous. Ovaries sessile at the 

 bottom of the calyx, in fruit enclosed by the fleshy calyx. 



Styles cohering in a column. 1. B. setigera. 

 Styles distinct. 



Leaflets not glandular beneath . 



Infrastipular spines absent or small. 2. B. Arkansana. 



Infrastipular spines present, conspicuous. 3. B. humilis. 



Leaflets glandular beneath. 4. B. rubiginosn. 



1. R. setigera Michx. Prairie Rose. Somewhat climbing, 4°-8° 

 high : stems armed with stout prickles : leaflets about three, sharply ser- 

 rate : flowers 2^-3^ broad : sepals deciduous. — Common in low grounds 

 and prairies. June. 



2. R. Arkansana Porter. Wild Rose. 1°-3° high : stems prickly to 

 nearly smooth : infrastipular spines rarely present : leaflets 5-11, oblong- 

 elliptical to obovate, cuneate or rounded at base, sharply serrate, glabrous 

 to strongly pubescent : flowers 2^ broad, one-many : sepals persistent, 

 spreading or erect in fruit. — Common on prairies and in dry places. 

 June. 



3. R. humilis Marsh. Wild Rose Closely resembles i?. ^?A-aHSrtJirt, 

 but infrastipular spines present, and conspicuous : sepals deciduous in 

 fruit. — Rocky barrens, Swope Park to Raytown. June. 



4. R. rubiginosa L. Sweetbrier. 4°-6° high : stems armed with 

 stout recurved spines : leaflets 5-7, oval, often doubly serrate : flowers 

 few : sepals deciduous. Sparingly naturalized north of Lee's Summit 

 and near Independence. June. 



Family 59. POMACEAE L. 

 Trees or shrubs with alternate leaves and perfect regular flowers. 

 Sepals and petals five each. Stamens numerous. Ovary inferior, 1-5- 

 eelled, with 1-2 ovules in each cell. Fruit a fleshy pome. 



