48 JOURNAL OF THE ARNOLD ARBORETUM [vol. hi 



X Rhododendron holmleaense R. discolor x ([catawbiense x ?]), hybr. nov. 

 Shrub: Young branchlets with scattered minute stipitate glands, soon 

 glabrous; winter-buds ovoid to ovoid-oblong, pointed, to 3.5 cm. long, 

 with many ovate, acuminate or mucronate greenish scales, puberulous 

 outside, glabrous and lustrous inside except toward the apex, fimbriate 

 on the margin with brown elongated glands and toward the apex with 

 villose ferrugineous hairs. Leaves oblong-lanceolate to oblong-oblanceo- 

 late or elliptic-oblong, 8-15 cm. long, 3.5-5.5 cm. broad, acute or obtusish 

 and mucronulate at apex, abruptly contracted and rounded at the base 

 or sometimes broadly cuneate, dark green and finely impressed-reticulate 

 above, pale grayish green or glaucescent beneath and finely reticulate 

 with the areoles between the veinlets slightly elevated, glabrous except 

 a very slight floccose tomentum on the upper surface when unfolding, 

 with 12-16 lateral veins; petioles stout, 1-2 cm. long, stipitate-glandular 

 at first, soon quite glabrous. Flowers in 10-15-flowered umbel-like 

 racemes; rhachis 2-5 cm. long, glabrous; pedicels 2.5-4 cm. long, rather 

 densely but minutely stipitate-glandular, calyx with broadly semiorbicular 

 to nearly obsolete lobes, not more than 2 mm. high, minutely glandular- 

 ciliolate, outside glabrous or very slightly stipitate-glandular; corolla 

 rotate-campanulate, 7-9 cm. across, pale amaranth pink to nearly white 

 the upper lip below the lobe with dark markings of Pompeian red to 

 madder brown often confluent toward the base, or without any markings, 

 lobes 5-6, semiorbicular to orbicular-ovate, about 3 cm. long or 3.5-4 

 cm. broad, rounded or slightly emarginate at apex and plane or slightly 

 undulate at the margin, tube about 3 cm. long, slightly pilose inside 

 stamens 10-12, very unequal, 2-3.5 cm. long, pilose on the lower third 

 whitish; anthers ochraceous and 4 mm. long or more or less abortive; 

 style 3.5-4 cm. long, reaching nearly to the middle of the upper lobe 

 strongly curved upward near apex, stipitate glandular only at base or 

 nearly the whole length, whitish, stigma capitate, broad and flattened; 

 ovary stipitate-glandular sometimes interspersed with a few scattered 

 hairs, usually 8-celled, sometimes 6-7-celled. 



Cultivated at Holm Lea, Brookline, Mass., and at the Arnold Arboretum; speci- 

 mens of several forms including the type collected at Holm Lea in May, 1921 

 (flowering in the greenhouse) and at the Arnold Arboretum on June 7, 1921, arc 

 preserved in the herbarium of the Arnold Arboretum. 



This beautiful hybrid was raised by Charles Sander in 1915 at Holm 

 Lea from R. discolor Franchet fertilized with the pollen of an unnamed 

 hybrid seedling form of R. catawbiense. A large number of seedlings 

 were raised of which some were almost indistinguishable from R. dis- 

 color, while others were clearly intermediate between that species and 

 R. catawbiense. These intermediate forms differ from R. discolor in the 

 generally smaller and comparatively broader leaves and shorter petioles, 

 in the glandular pedicels, the 5- or 6-lobed corolla with a short much 

 wider tube and usually spotted upper lip, in the 10-12 stamens more or 

 less pilose toward the base and in the style being usually glabrous at 



