Valley are quite rare or entirely lacking in the valley. Among 

 these are teasel, hepatica, dicentra, claytonia, bloodroot, barberry, 

 walking fern and some of the violets. A number of Southern 

 and Western species have of late years been introduced in this 

 region through the railroads. Weeds that were rare in Lacka- 

 wanna County are now becoming pests. 



Prof. C. S. Sargent, Director of the famous Arnold 

 Arboretum, a world authority on trees and shrubs, after three 

 botanical visits to Scranton, expressed the opinion that there 

 are at least forty species or forms of the Crataegus (hawthorn) 

 in the Lackawanna Valley. Professor Sargent has classified 

 twenty-seven of these, giving the handsomest of our local species 

 the name of Crataegus twiningi. This species, an Intricatae, is 

 described at length in the proceedings of the Academy of Natural 

 Sciences of Philadelphia, Vol. LXII, Part I, 1910, pages 230 

 and 231. Professor Sargent adds to the description: "This 

 species is named for its discoverer, Mr. Alfred Twining of Scran- 

 ton, who first called attention to the richness of Lackawanna 

 County in forms of Crataegus." 



The following interesting points and altitudes from which 



the greater part of the Flora in this check list was gathered are : 



The beautiful double domes of the Elk Mountains (south dome 



2,575 feet, north dome 2,700 feet), exceeded only a few feet 



by the Blue Knob, the highest mountain in the State ; Bald Mount, 



2,385; Clarks Summit, 1,239; Elmhurst, 1,397; Moscow, 1,555; 



Gouldsboro, 1,890; Tobyhanna, 1,929; Ararat Summit, 2,023; 



Uniondale, 1,693; Carbondale, 1,079; Archbald, 965; Pittston, 



573; Kingston, 550; Crystal Lake, 1,755; Campbell's Ledge (Dial 



Rock), 1,302; Penobscot Knob, 2,220; Pocono Knob, 2,225; 



Ararat Peak, 2,600; Sugar Loaf, 2,450; Mount Anonymous, 



1,596; Scrub Oak. 2,092; Big Shiney, 2.320; Moosic Mountain 



Range, from 2,000 to 2,120. 



Alfred Twining. 

 Scranton, Pa., 



Feb. 1, 1917. 



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