18 



HANDBOOK 148, U.S. DEPARTMENT OF AGRICULTURE 



Plants with thorns (aborted twigs) in leaf-scar axils (thorns some- 

 times lacking on young or sucker shoots) ; leaves variable in shape 

 and lobing, usually wedge-shaped at base and lobed above middle, 

 firm, glossy on upper surface; fruits (pomes) berrylike, with 1-5 

 bony "seeds" (carpels), tipped by withering-persistent flower 

 parts, stalked, in clusters (cymes or corymbs); small trees or 

 erect shrubs, often in thicket's; moist sites, flood plains or river 



valleys, e. Oreg., e. Wash hawthorns (Crataegus spp.). 3 



[Alternate 6, p. 10.] 



17. Ripe fruits shiny purplish black (chestnut-colored in form 

 badia), hairless; thorns stout, to 1 inch long, often blunt; 

 twigs reddish brown, aging gray; leaves elliptic to reversely 

 egg-shaped, usually shallowly lobed and coarsely and un- 

 evenly saw-toothed above middle, entire or finely toothed 

 below middle; all parts hairless or nearly so when mature; 

 compact shrubs or trees to 35 feet high, common; type local- 

 ity, near Vancouver, Wash. 



black (or Douglas) hawthorn (Crataegus douglasii). 



3 Some hawthorns reportedly crossbreed naturally; some of the resultant hybrids 

 (with characteristics variously intermediate between those of their two parents) 

 can produce fertile seed without pollination. Each seedling so produced is exactly 

 like its hybrid parent. This specialized "vegetative" reproduction (apomicty) 

 probably accounts for some of the well-known hawthorn variability that has 

 resulted in the description of over 1,100 North American "species," and also for 

 some of the difficulties in identifying hawthorns. (See W. H. Camp, Ecological 

 Problems and Species Concepts in Crataegus. Ecology 23: 368-369. 1942). 



Black (or Douglas) hawthorn 



