ERICACEAE. — RHODODENDRON 539 
subtus pallidiora, leviter elevato-reticulata, costa media supra impressa subtus 
elevata, nervis utrinsecus 10-12 supra leviter impressis v. fere obsoletis subtus 
leviter elevatis; petioli crassi, 1-1.2 em. longi, juniores puberuli. Flores 10-12 v. 
plures, racemoso-umbellati; rhachis circiter 1 cm. longa, rufo-tomentosa; pedicelli 
graciles, 1-1.6 em. longi, tomento villoso cinereo-albido dense vestiti; bracteae 
oblongo-obovatae v. oblanceolatae, utrinque villosae; calyx minutus, cupularis, 
lobis 5, late triangularibus acutis 1-1.5 mm. longis sparse pubescentibus; 
corolla campanulata, 2.5-3 cm. longa ac lata, 5-loba, lobis rotundatis circiter 
1 cm, longis; stamina circiter 10, corollam subaequantia, filamentis 2-2.5 cm. 
longis dilatatis supra medium villosis, antheris pallide roseis; ovarium conicum, 
4-5 mm. longum, sparse albido-villosum; stylus curvatus, glaber, stigmate capi- 
tato. Capsula desideratur. 
Shensi: Tai-pei-shan, 1910, W. Purdom (No. 4). 
This species is closely related to R. brachycarpum G. Don, a Japanese species, 
Which has rather differently shaped leaves white or dun-colored on the under 
side, a more elongated inflorescence, longer pedicels and larger flowers. It is also 
related to R. Przewalskii Maximowicz which has broader leaves, usually subcor- 
date at the base and covered with rufous or pale tomentum beneath, glabrous 
pedicels and an umbellate inflorescence. 
This species is named for William Purdom, in charge of the Arnold Arboretum 
explorations in northern China during the years 1909, 1910 and 1911. 
Rhododendron gymnanthum Diels in Not. Bot. Gard. Edinburgh, V. 211 (Pl. 
Chin. Forrest.) (1912). 
Yunnan: Tse-kou, valley of upper Mekong river, T. Monbeig (No. 4). 
Our Specimens differ from Diels’ description in the longer calyx-lobes, in the 
ovary being 7-9 mm. long, and in the partly short-acuminate leaves. We consider 
„Species as closely related to R. irroratum Franchet and possibly some 
Specimens eolleeted in Yunnan by A. Henry (Nos. 10275, 10853, 11066, 11067, 
11067") and referred by Hemsley & Wilson (Kew Bull. Misc. Inform. 1910, 
112) to R. irroratum, might be considered as constituting a pubescent variety of 
R.gymnanthum. In his original description of that species (Bull. Soc. Bot. France, 
+ 280) Franchet describes the under surface of the leaves as glaucous and 
the ovary as densely clothed with brown glands. In all Henry’s specimens the 
eaves are pale green below and the ovary is not glandular but densely covered 
with rufous-gray tomentum. In No. 10853 the ovary is very sparsely tomentose. 
in the Botanical Magazine (LXX. t. 7361) of R. irroratum agrees with 
Franchet’s description except that the leaves are pale green below. Possibly the 
Species is very variable. Père Monbeig’s specimen is glabrous everywhere save 
the rhachis of the inflorescence, which is very sparingly puberulous and totally 
without glands. This and the racemose-umbellate inflorescence readily dis- 
mr from the R. irroratum Franchet, and from the specimens of Henry's 
above. 
According to the description this new species is also near R. lukiangense Fran- 
Chet which has atten bracts, shorter pedicels, smaller, differently shaped 
Wers and inconspicuous calyx-teeth. 
Group f. 
Corolla 7-9-lobed (5-lobed in the preceding groups of this subgenus). Leaves 
E 2m» me to abruptly contracted at the base (cuneate in a variety of 
