106 JOURNAL OF THE ARNOLD ARBORETUM [vol. iv 



at base, up to 5 or 6 cm. long and 5 or 5.5 cm. wide, their petioles stouter, 

 2.5-3 cm. long. Flowers 8-10 mm. in diameter, opening from the 8th 

 to the 20th of May on long slender pedicels in mostly 20-25-flowered rather 

 open glabrous corymbs; calyx-tube broad-obconic, glabrous, the lobes 

 small, nearly triangular, apiculate, glabrous, reflexed after anthesis; 

 stamens 15-20; anthers pale yellow; styles 3-5, usually reduced to 1 by 

 abortion of all but one carpel, persistent on the fruit. Fruit ripening in 

 October and persistent on the leafless branches at least until the beginning 

 of the new year, globose to subglobose, scarlet, 5-7 mm. in diameter, 

 the calyx persistent or deciduous, closely appressed to the fruit or raised 

 on a short neck, with enlarged spreading lobes; flesh thin, yellow, dry 

 and mealy; nutlets often reduced to one by abortion, rounded and broader 

 at the apex than at the acute base, rounded and only slightly ridged on 

 the back, distinctly concave on the inner faces, about 4 mm. long and 2 

 rum. wide, the narrow pale hypostyle extending nearly to the middle. 



A tree 8-10 m. high with a tall trunk covered with dark scaly bark, 

 spreading branches forming a wide symmetrical head, and slender nearly 

 straight glabrous branchlets pale green when they first appear, becoming 

 light chestnut-brown before the end of their first season and dark gray- 

 brown the following year and armed with numerous straight slender spines 

 2-.'5 cm. in length. 



North Carolina. Guilford Coun ty, low wet bottoms, near Greensboro, 

 Robert C. Young, April and May 8, 1921, T. G. Harbison, No. 6110, May 9, 1922, 

 Nos. 6028, 6028a (type), May 23, Oct. 9, 1922. Wake County, near Raleigh,' 

 T. G. Harbison, No. 6038, Oct. 8, 1922. 



South Carolina. Kershaw County, banks of the Wateree River, near 

 Camden, Susan Delano McKelvey, Dec. 26, 1922, T. G. Harbison (No. 6129) 

 May 23, 1922, Nos. 625 and 628, Oct. 6, 1922. 



This is one of the most interesting species of Crataegus which has been 

 discovered recently in the United States. Its relationship is with the 

 Washington Thorn (C. Phaenopyrwn Medicus) which it resembles in its 

 small flowers and fruit, in the fact that the primary veins of the leaves 

 extend to the sinuses of the leaves as well as to the points of the lobes, 

 in the style persistent on the fruit, and in the general habit of the tree. 

 It differs from that species in its normally acutely 3-lobed leaves, cuneate 

 and decurrent at base on the petiole, not cordate and not rounded except 

 on vigorous shoots. In Crataegus Phaenopyrum the calyx is deciduous 

 from the fruit by a circumsissiie line and in falling leaves the top of the 

 nutlets exposed, a character which has not been noticed in any other 

 species of the genus. On the fruit of Crataegus Youngii the line of separ- 

 ation can often be distinguished but the calyx is usually persistent and 

 if it does fall the end of the nutlets does not become exposed. The nutlets 

 of the new species are narrower and more concave on the inner face, with 

 a less conspicuous hypostyle. From the other Microcarpae it differs 

 in its yellow anthers. The nearly constant abortion of all but one carpel 



