1921| REHDER. NEW SPECIES, VARIETIES AND COMBINATIONS 45 



Originated in the garden of Mrs. Bayard Thayer at Lancaster, Massa- 



chusetts. 



Ma 



July 27, 1920, C. S. Sargent (type); Arnold Arboretum, July 29, August 

 25 and September 28, 1920, Alfred Rehder. 



This hybrid was raised by Mr. William Anderson, gardener to Mrs. 

 Bayard Thayer at Lancaster, Mass., from seed of Vitis Coignetiae Planch, 

 apparently fertilized by a nearby V. vulpina L. I have specimens of 

 both parent plants before me; the V. Coignetiae is not the typical densely 

 tomentose form but the var. glabrescens Nakai which at maturity is only 

 very thinly covered by a cobwebby tomentum, so that the under side 

 appears grayish green or greenish and not densely rusty-tomentose; the 

 V. vulpina is typical in the shape and serration of the leaves, but the veins 

 and stronger veinlets beneath are pilose. From V. Coignetiae the new 

 hybrid is easily distinguished by the smaller more deeply 3-lobed leaves, 

 the coarser serration with triangular, acute or short-acuminate teeth 

 and by the very slight or entirely absent floccose tomentum on the under 

 side of mature leaves. From V. vulpina it differs chiefly in the usually 

 larger less deeply 3-lobed leaves, in their narrower basal sinus its sides 

 diverging at an acute or right angle, in the broader and shorter scarcely 

 acuminate teeth and in the more pubescent under side. The different 

 plants of this hybrid show a great variation and represent almost all in- 

 termediate stages between the two parent species; some being so near to 

 V. vulpina, that they can only be distinguished from it by the narrow 

 basal sinus of leaves, very wide and nearly truncate near the petiole in 

 V. vulpina. 



Cornus Dunbarii (C. asperifolia x macrophylla) , hybr. nov. 



Tall shrub; becoming tree-like, with upright or ascending branches 

 young branchlets slightly quadrangular with sparse short appressed 

 hairs, dull purple the second year and usually soon becoming brown and 

 developing numerous short longitudinal fissures. Leaves elliptic-ovate 

 to oblong-ovate, 6-12 cm. long or on vigorous shoots to 16 cm. long, 

 2.5-6 cm. broad, long-acuminate, broad-cuneate or rounded at the base, 

 dark yellowish green above and slightly rough from short hairs, glaucous 

 beneath, rather densely covered with loosely appressed or partly slightly 

 spreading, straight or partly curved hairs, with 5-7 pairs of veins prom- 

 inent and yellowish beneath, like the midrib furnished with sparse ap- 

 pressed or slightly spreading hairs or nearly glabrous; petioles 1-2 cm 

 long, with short appressed hairs. Flowers in rather dense often slightly 



paniculate corymbs 5-6.5 cm. across; peduncle 3-3.5 cm. long, minutely 



appressed pubescent with short fulvous hairs, the branchlets of the corymb 

 more densely pubescent with similar but whitish and partly slightly 

 spreading hairs; pedicels very short; ovary densely appressed-pubescent; 

 calyx-teeth subulate to 0.5 mm. long, exceeding the disk; petals oblong- 

 lanceolate, 3.5-4 mm. long; filaments slightly shorter; style 2.5-3 mm. 



