188 



THE 



[vol. Ill 



and primary veins, and at maturity thin, yellow-green and slightly rough- 

 ened above by short white hairs, pale and glabrous or occasionally slightly 

 villose toward the base of the prominent midrib below, 1.5-2 cm. long 

 and 1-1.5 cm. wide, with three or four pairs of primary veins extending 

 to the points of the lobes, or 3-nerved from the base; petioles slender, 

 wing-margined to the middle, densely villose early in the season, becoming 

 nearly glabrous in the autumn, 5-6 mm. in length; leaves on vigorous 

 shoots ovate, broad and rounded at base, acute at apex, often deeply 

 lobed, 2-2.5 cm. long and wide. Flowers appearing after the middle of 

 April, small, in 4- or 5-flowered lax glabrous corymbs; calyx broad- 

 obconic, slightly villose, the lobes slender, acuminate, obscurely serrate, 

 glabrous on the outer surface, villose on the inner surface; stamens 20; 

 anthers pale yellow; styles 4 or 5. Fruit ripening the middle of October, 

 subglobose, orange-red, 4-5 mm. in diameter, with thin dry flesh; the 

 calyx enlarged and prominent, with erect or spreading glabrous lobes 

 and a wide shallow cavity broad in the bottom; nutlets 4 or 5, rounded 

 and rather broader at apex than at base, only slightly grooved on the 

 back, 4 mm. long and 2.5-3 mm. wide, the broad pale hypostyle extending 



to below the middle. 



A shrub 3 m. high, with stems covered with thin pale bark flaky near 

 their base, and slender unusually zigzag branchlets red-brown and slightly 

 villose when they first appear, soon glabrous, ashy gray at the end of their 

 first season and horribly armed with many slender straight or slightly 

 curved chestnut-brown ultimately gray spines 2.5-5 cm. in length. 



Texas. Uvalde C o u n t y, in the rocky bed of a creek usually dry, but 

 flooded during a few hours two or three times during the year, near Uvalde, 

 E. J. Palmer, Nos. 11348, 12379 (type), 12973, March 22, June 17, October 12, 

 1917; Nos. 13322, 13498, 13699, 14496, April 6, May 5, May 26, September 24, 1918. 



In its unusually zigzag branches, numerous long slender spines and 

 minute fruit this is perhaps the most distinct species of the Virides Group. 

 The fact that it inhabits a region of rare rainfall where the soil in which 

 it grows is only thoroughly wet two or three times in the year would be 

 remarkable for any species of Crataegus; it is the more remarkable for 

 a species of this Group, for the Virides, growing usually in low ground, are 

 moisture loving plants. It is unfortunate that Mr. Palmer has been 

 able to find only a single plant. 



Crataegus tripartita (§ Virides), n. sp. 



Leaves usually elliptic, acute or acuminate at apex and gradually 

 narrowed to the cuneate base, or rarely ovate or obovate and broad- 

 cuneate or rounded at base, finely serrate above the middle with straight 

 or slightly incurved teeth, rarely slightly lobed, often furnished below 

 early in the season with axillary tufts of snow-white pubescence, other- 

 wise glabrous, subcoriaceous, yellow-green, lustrous above, 3-4 cm. long, 

 1.5-2.5 cm. wide, with a thin midrib and slender prominent veins deeply 

 impressed on the upper surface; petioles slender, narrowly wing-margined 



