1923] SARGENT, NOTES ON NORTH AMERICAN TREES 105 



with red when they unfold, and slightly villose on the upper side of the 

 midrib early in the season, at maturity thin, glabrous, dark yellow-green 

 on the upper surface, paler on the lower surface, 4-5 cm. long and 3.5-4.5 

 cm. wide, with a prominent midrib and slender primary veins; petioles 

 slender, wing-margined at apex by the decurrent blade of the leaf, 1-1 .5 cm. 

 in length; leaves on vigorous leading shoots ovate to suborbicular, often 

 laterally lobed with acuminate lobes, as seen not more than 4.5 cm. long 

 and 3.5-4 cm. wide. Flowers appearing from the middle to the end of 

 April, about 1.5 cm. in diameter, on slender pedicels in glabrous compact 

 mostly 4- or 5-flowered corymbs, the bracts and bractlets leaf-like, oblong- 

 ovate, acuminate, glandular, early deciduous; calyx-tube broad- obconic, 

 glabrous, the lobes gradually narrow r ed from a wide base, short, acute, 

 laciniately glandular-serrate, glabrous on the outer surface, sparingly 

 villose on the inner surface; stamens 10; anthers rose-color; styles 3 or 4. 

 Fruit ripening the end of September, on short erect or spreading pedicels, 

 in few-fruited clusters, short-oblong to slightly obovoid, dull orange- 

 brown, about 1 cm. long and broad, the calyx little enlarged with spreading 

 lobes, and a deep cavity pointed in the bottom; flesh very thin and dry; 

 nutlets 3 or 4, gradually narrowed and rounded at the ends, rather broader 

 at base than at apex, only slightly ridged on the back, 7 or 8 mm. 

 long and 5 or 6 mm. wide, the dark conspicuous hypostyle extending for 

 about a third of their length. 



A shrub 2-3 m. high, with slender zigzag glabrous branchlets dark 

 chestnut-brown and lustrous when they first appear, becoming dark 

 gray-brown in their second year, and armed with many stout or slender 

 nearly straight spines 2.5-4 cm. in length. 



Oklahoma. La Flore County, rocky slopes and open hillsides near Page, 

 E. J. Palmer, No. 2092, April 25, 1921, No. 20629 (type) and 20630, September 

 24, 1921, Nos. 20921, 20925, April 25, 1922, Nos. 20941, 20986, 20987, April 28, 



1922. 



This species most resembles Crataegus padifolia Sarg. from Swan, 

 Christian County, Missouri, which differs from it in its long ovate leaves 

 and yellow anthers slightly tinged with pink, and in its smaller subglobose 

 fruit. 



Crataegus Youngii (§ Microcarpae), n. sp. 



Leaves ovate, cuneate and slightly decurrent on the petiole at base, 

 3-lobed with acute or acuminate lobes, the terminal lobe often divided 

 into small secondary lobes, remotely crenulate-serrate usually only above 

 the middle, glabrous or early in the season villose along the midrib above, 

 dark yellow on the upper surface, paler on the lower surface, 2. -3 cm. 

 long and 2-2.5 cm. wide, with a slender midrib and obscure primary 

 veins extending to the point of the lobes and often also to the base of the 

 sinus; petioles slender, 1-2 cm. in length; leaves on leading vigorous shoots 

 obscurely laterally or obscurely 3-lobed, more abruptly cuneate or rounded 



