538 WILSON EXPEDITION TO CHINA 
The open campanulate flowers with the large calyx, leaves cordate or truncate 
at the base, with a metallic-green luster, readily distinguish R. Souliei from all 
related species. 
Rhododendron Williamsianum Rehder & Wilson, n. sp. 
Frutex 1.50 altus, ramosu; ramuli graciles, hornotini sparse 
pilis glanduliferis instructi, annotini glabri, nitiduli, pallide cinereo- 
fusci; gemmae ovoideae, acutae, purpurascentes, perulis extus glabris 
ciliolatis. Folia coriacea, ovata v. rotundato-ovata, apice rotundata 
apiculata, basi plerumque leviter cordata, rarius truncata, margine 
reflexa, 1.74.2 em. longa et 1.3-3.2 cm. lata, glabra, supra obscure 
viridia, leviter elevato-reticulata, subtus flavescenti-glauca, obsolete 
elevato-reticulata; petioli 1-1.5, saepe sparsissime glanduloso-pilosi, 
purpurascentes. Flores 3-5, umbellato-racemosi; pedicelli sparse 
glanduloso-pilosi, purpurascentes, interdum glabri; calyx minutus, 
obsolete 5-dentatus, sparse stipitato-glandulosus praesertim ad mar- 
ginem; corolla aperte campanulata, 3-3.5 em. longa et 44.5 em. 
lata, glabra, pallide rosea maculis destituta, 5-loba lobis suborbicu- 
laribus 1.2-1.4 em. longis; stamina plerumque 10, longiora medium 
loborum attingentia, filamentis glabris; ovarium conicum, glanduloso- 
pilosum, 4-5 mm. longum; stylus curvatus, exsertus, totus sparse 
glandulosus glandulis infra medium stipitatis, stigmate capitato. 
Capsula cylindrica, circiter 1.5 em. longa, 5 mm. diam., glabra v. 
sparse glandulis stipitatis instructa, pallida; semina cinnamomea, 2- 
2.5 mm. longa, utrinque alata. 
Western Szech'uan: Wa-shan, thickets covering cliff, rare, alt. 
2800 m., June and October 1908 (No. 1350). 
This pretty and distinct species is apparently most nearly related to R. Soulici 
Franchet, which is easily distinguished by its rather large membranous calyx, 
differently shaped flowers and larger leaves, merely pale below. It may also 
compared with R. rotundifolium David, which is a much more vigorous species, 
easily distinguished by its totally different leaves and 7-lobed corolla. This t 
species is apparently very local, occurring only in isolated places on the 
Wa-shan. Bt 
This species is named for Mr. J. C. Williams of Caerhays Castle, Corn ir 
England, the first amateur to appreciate the horticultural value of the Bg ore 
dendrons of western China; in his garden the best collection of these new i 
ductions is now to be found. 
'To this group also belong the following species: 
Rhododendron Purdomii Rehder & Wilson, n. sp. ? libus 
Frutex robustus ramulis crassis junioribus puberulis; gemmae perulis o 
v. oblongis puberulis per plures annos persistentibus. Folia coriacea, obl 
lanceolata v. oblonga, acuta, basi cuneata, margine revoluta, 6-9 cm. longa 
2.5-3.5 cm. lata, utrinque glabra, supra laeta viridia, nitida, leviter ruguloss, 
