32 



SELECTED WESTERN FLORA 



1. QUERCUS. Oak. 



Sterile flowers in slender naked catkins; stamens 3-12; calyx. 

 2-8-parted; fertile flowers not in catkins but sometimes clustered; 

 ovary enclosed in a scaly cup-like involucre forming a fruit called 

 an acorn. Trees with heavy durable wood, rough bark, and usually 

 sinuate-pinnatifid leaves. 



1. Q. macrocarpa, Miohx. Bur Oak. 



Leaves lyrately pinnatifid or deeply sinuate; 

 cup deep, almost enclosing the nut, and furnished 

 with a fringe of bristles around the edge. A 

 valuable tree in moist climates, but in our range 

 seldom reaching large size. Rich soil, Man. north 

 to Lake Winnipegosis and into eastern Sask. 



Fig. 29. — Quercus ma- 

 crocarpa. 



XXI. URTICACE.*; (Nettle Family). 



Herbs, trees, or shrubs, with alternate or opposite stipulate leaves 

 (stipules often deciduous) and monoecious, dioecious, or (in the elm) 

 perfect flowers; calyx free from the ovary; ovary 1 or 2-celled 

 forming a 1-seeded fruit; stamens as many as the lobes of the 

 calyx., 



1. tJLMUS. Elm. 



Flowers perfect; calyx 4-9-cleft, bell-shaped; sta- 

 mens 4-9, with slender filaments; ovary 1 or 2-celled 

 with a single ovule in each cell; fruit winged all 

 around. Trees with tough wood and rough scaly 

 bark. 



1. U. americlna, L. American White Elm. 



Buds and branchlets smooth; leaves obovate or oval, 

 abruptly pointed, soft-pubescent beneath, and usually 

 oblique at the base; flowers in close fascicles. A rough- 

 barked tree, usually with long spreading branches, and 

 often with drooping branchlets, much used for ornamental Fig. 30. — Ul- 

 purposes. Rich moist soil, especially along rivers, Man. raaa ameri- 



and E. Sask. cana. 



2. CELTIS. Hackbbrey. 



Flowers monceoious with sometimes a few perfect^ calyx 5 or 6- 

 parted, persistent; stamens the same number as the calyx lobes; 

 ovary 1-eelled with a single ovule; Stigmas 2, long, recurved; fruit 

 a drupe. Trees with large pointed leaves, very oblique at the base. 



