312 



MALACEAE. 



VOL. II. 



45. Crataegus populnea Ashe. Gruber's Thorn. 

 Fig. 2379. 



C. populnea Ashe, Ann. Cam. Mus. i : 395. 1902. 

 C. stolonifera Sarg. Bot. Gaz. 35: 109. 1903. 



A shrub or small tree, sometimes 20 high, with a 

 flattened round crown. Spines i'-2' long; leaves mem- 

 branous, slightly villous above, becoming glabrate, 

 broadly ovate to elliptic-ovate, i'-2f long and wide, 

 acute to acuminate at the apex, broadly cuneate to 

 truncate at the base, those of the vegetative shoots usu- 

 ally cordate, serrate or twice serrate, the lobes broad, 

 acute or none; corymbs glabrous; flowers 8"-io" broad; 

 stamens 5-10; anthers pink; styles and nutlets usually 

 3 or 4; fruit glabrous to short-ellipsoid, scarlet, $"-/" 

 thick, calyx-lobes appressed or spreading; flesh yellow. 



Low grounds, southern Ontario to Pennsylvania and Dela- 

 ware. May ; fruit ripe September. 



46. Crataegus aspera Sargent. Rough-leaved Thorn. Fig. 2380. 



Crataegus aspera Sarg. Trees & Shrubs 2 : 67. pi. 131. 1908. 

 C. bracteata Sarg. Rep. Mo. Bqt. Card. 19: 91. July 1908. 



A shrub, sometimes 7 high, with slender zigzag 

 branchlets. Spines numerous, curved, ii'-2j' long; 

 leaves ovate, ij'-2i' long, f-2' wide, acute or acumi- 

 nate at the apex, rounded or truncate at the base, finely 

 serrate or doubly serrate, with 3 or 4 pairs of acute 

 lobes, yellow-green, membranous, appressed-pubescent, 

 becoming scabrate above, tomentose beneath ; petioles 

 tomentose, i'-ii' long; corymbs few-flowered; pedicels 

 slightly pubescent, becoming glabrous; flowers 8" or 

 9" broad; calyx-lobes triangular; stamens about 10; 

 styles and nutlets usually 4 or 5; fruit short-ellipsoidal 

 to subglobose, scarlet, very pruinose, 5" or 6" thick ; 

 calyx-tube little enlarged, the lobes obtuse, spreading, 

 often deciduous; flesh thin. 



Thickets, southern Missouri. April-May ; fruit ripe No- 

 vember. 



47. Crataegus Jesupi Sargent. Jesup's 

 Thorn. Fig. 2381. 



Crataegus Jesupi Sarg. Rhodora 5: 61. 1903. 



A large shrub, sometimes 20 high, with ascend- 

 ing branches. Leaves elliptic-ovate, i*'-3' long, 

 i '-2' wide, acute or acuminate at the apex, broadly 

 cuneate to truncate-cordate, serrate or doubly ser- 

 rate with 4 or 5 pairs of acute lobes, yellow-green 

 above, paler beneath, glabrous; corymbs glabrous; 

 flowers about 10" broad, calyx-lobes entire; stamens 

 about 10 ; anthers dark red; styles and nutlets usu- 

 aljy 3 or 4; fruit short-ellipsoid to pyriform, about 

 5" thick, dark red, slightly angled, devoid of bloom 

 when mature; calyx-lobes mostly deciduous; flesh 

 firm at maturity. 



Western Vermont to southwestern Wisconsin, south 

 to Pennsylvania. May; fruit ripe October. 



