1905.] NATURAL SCIENCES OF PHILADELPHIA. 653 



A shrub about 2 m. high, with numerous ascending stems covered 

 with smooth greenish-gray bark, and slender zigzag branchlets marked 

 by numerous small pale lenticels, light orange color when they first 

 appear, bright chestnut-brown and very lustrous during their first 

 winter, becoming light gray tinged with red, and armed with numerous 

 stout or slender nearly straight dark purplish shining spines 4-6 cm. 

 long. 



Bucks county: Roadsides near Sellersville, C. D. Fretz (No. 119, 

 type!), September, 1899, May and October, 1901. 



This species is named in memory of Louis David de Schweinitz 

 (1780-1834), the distinguished Pennsylvania botanist. 

 17. Crataegus darlingtoniana n. sp. 



Leaves oblong-ovate, acuminate, gradually narrowed and concave- 

 cuneate at the entire or serrate base, sharply doubly serrate above, 

 with straight gland-tipped teeth, and divided above the middle into 3 

 or 4 pairs of narrow acute lobes, at maturity thin but firm in texture, 

 glabrous, dark yellow-green on the upper and pale yellow-green on 

 the lower surface, 3.5-4 cm. long and 2-2.5 cm. wide, with slender red 

 or reddish midribs, and thin primary veins extending obliquely to the 

 points of the lobes ; petioles very slender, slightly grooved on the upper 

 side, wing-margined at the apex, glandular, with minute dark glands, 

 reddish toward the base, 1-1.2 cm. in diameter; leaves on vigorous 

 shoots broadly ovate, sometimes rounded at the wide base, more 

 coarsely serrate and more deeply divided into broad lateral lobes, and 

 sometimes 5-6 cm. long and 3.5-4 cm. wide, with stout petioles broadly 

 winged nearly to the base. Flowers unknown. Fruit ripening early 

 in October, on short slender pedicels, in few-fruited clusters, short- 

 oblong to depressed-globose, full and rounded at the ends, bright 

 canary-yellow, 1.2-1.4 cm. in diameter; calyx with a short tube and a 

 broad deep cavity, the lobes deciduous from the ripe fruit; flesh thin, 

 sweet, light yellow; nutlets 3 or 4; rounded and obtuse at the ends, 

 ridged on the back, with a high narrow or broad grooved ridge, about 

 7 mm. long and 5 mm. wide. 



A shrub 1-2 m. high, with slender nearly straight bright chestnut- 

 brown lustrous branches, becoming dull red-brown in their second year 

 and marked by numerous small oblong pale lenticels. 



Chester county: Serpentine Ridge, near West Chester, Canhy and 

 Smith (No. 228, type!), October 8, 1902. 



The dry ridge where this plant and several other dwarf forms of 

 Crataegus were found by Canby and Smith was burnt over after their 

 visit. The plants were all killed to the ground, and, although the 



