PLUM FAMILY 165 



on the calyx, ovary 2-celled, styles 2, fruit globose ; flowers solitary or in 

 sessile 2-3-flowered umbels ; leaves clustered at the ends of the branches ; 

 low shrub. 

 Stems 2-6 ft. high ; leaves linear-oblanceolate, toothed 



or entire ; flowers pink P. ramosissimum 



SORBUS Linne 1753 MOUNTAIN ASH 

 (Lat. name of the pear) 



Sepals 5, united into an urn-shaped calyx, petals 5, white, stamens 

 many, inserted with the petals on the calyx-tube, ovary inferior, styles us- 

 ually 3, fruit a small red berry-like pome; flowers in terminal branched 

 cymes; leaves alternate, pinnate, the leaflets toothed; trees or shrubs. 

 Trunks 10-30 ft. high; leaflets 7-15, serrate, oblong, 2- 



5 cm. long; flowers 7-10 mm. wide P. sambucifolia 



PRUNACEAE PLUM FAMILY 



Sepals 5, united into a bell-shaped tube, free from the ovary, petals 

 5, white or pink, stamens many, inserted with the petals on the calyx, pistil 

 1, 1 -celled, becoming a fleshy 1 -seeded fruit with a stone; flowers regular, 

 usually perfect, solitary or in racemes, umbels or corymbs ; trees or shrubs 

 with alternate, simple, toothed leaves. 



PRUNUS Linne 1753 PLUM, CHERRY 



(The Latin name) 



PL 26, fig. 13-15. 



Characters of the family. 



1. Flowers in umbels, appearing with or before the 



leaves ; fruit 12-30 mm. in diam. 



a. Low shrubs, 1-4 ft. high ; leaves elliptic to 



spatulate, toothed ; flowers 8-12 mm. wide P. pitmila 



b. Tall shrubs, 6-20 ft. high; flowers 12-25 mm. 



wide 



(1) Leaves ovate, long-pointed; fruit 20-30 



mm. wide P. americdna 



(2) Leaves lanceolate, acute; fruit 12-20 mm. 



wide P. angustifoHa 



2. Flowers in corymbs or racemes, appearing after 



the leaves 

 a. Flowers in corymbs, 12-15 mm. wide; fruit 



red P. pennsilvdnica 



