ROSACEAE. 137 



193. ROSA. Rose. 



Erect or climbing shrubs, usually with prickly stems; leaves 

 alternate, odd-pinnate, with adherent stipules; leaflets mostly 

 serrate; flowers solitary or in corymbs; receptacle-tube cup or 

 urn-shaped, becoming fleshy in fruit, usually 5-lobed, without 

 bractlets; petals 5, large, obcordate; stamens numerous, on the 

 receptacle-tube; styles distinct or united; carpels numerous, 

 sessile, within the receptacle-tube; akenes numerous, enclosed 

 •in the berry-like receptacle-tube. 



Flowers small, about 2 cm. in diameter; calyx-lobes deciduous 



from the fruit. R. gymnocarpa. 



Flowers large, 3 cm. or more in diameter; calyx-lobes persistent. 



Flowers mostly solitary; fruit globose, 2 cm. broad. R. nutkana. 



Flowers in corymbs; fruit ovoid or oblong, not more than 



1 cm. broad. R. pisocarpa. 



Rosa gymnocarpa Nutt. Small shrub, about 1 m. high, armed with 

 numerous slender straight prickles; leaflets 5-9, elliptic, cuneate at base, 

 serrate, nearly glabrous, 5-20 mm. long; serratures and petioles glandular; 

 flowers mostly solitary, about 2 cm. in diameter; calyx-lobes acuminate, not 

 foliaceous, appendaged, deciduous from the fruit; fruit oblong or pear-shaped, 

 about 1 cm. long. In dry woods. 



Rosa nutkana Presl. Stout, 1-2 m. high, armed with few but stout prickles; 

 leaflets 5-7, ovate or elliptic, obtuse, coarsely serrate, 1-3 cm. long, glabrous 

 or somewhat pubescent, usually glandular on the petioles and serratures; 

 flowers mostly solitary, 4-5 cm. broad; calyx-lobes glandular, foliaceous, 

 appendaged, persistent; receptacle-tube globose, smooth; fruit globose, 2 cm. 

 in diameter; seeds large. Common. 



Rosa nutkana macdougali (Holzinger) Piper. Receptacle-tube and fruit 

 densely hispid-prickly. Common. 



Rosa pisocarpa Gray. Very similar to R. nutkana, the leaves usually! 

 finely pubescent; flowers smaller, about 3 cm. in diameter, usually in corymbs; 

 fruit ovoid or oblong, 5-10 mm. in diameter. Common in low places. 



194. ALCHEMILLA. 



Low annual or perennial herbs; leaves palmately lobed or 

 compound, with sheathing stipules; flowers perfect, small, green- 

 ish, in corymbs; calyx 4-5-lobed, with as many minute bractlets; 

 petals none; stamens 1-4, very small; styles basal or lateral; 

 carpels 1-4, distinct, free from the calyx-tube; akenes 1-4, 

 enclosed in the receptacle. 



Alchemilla arvensis occidentalis (Nutt.) Piper. Annual, 2-8 cm. high, 

 simple or branched below, sparsely hairy; leaves short-petioled, fan-shaped, 

 3-parted, the lobes acutely 2-3-cleft; stipules conspicuous, cleft; calyx 1-1.5 

 mm. long, acutely 4-cleft, the bractlets minute; akenes ovate, pale, 1 mm. 

 long. Stony soil, not rare. 



