504 WILSON EXPEDITION TO CHINA 
Rhododendron Sargentianum Rehder & Wilson, n. sp. 
Frutex 30-60 cm. altus, ramosiosimus ramis erectis v. adscendenti- 
bus; ramuli hornotini et annotini fusco-tomentosi, tarde glabrescentes, 
vetustiores cinereo-fusci, cortice in lamellas tenues solubili et corticem 
interiorem flavido-cinereum detegente; gemmae parvae, ovoideae, 
acutae, perulis paucis acutis tomentosis ciliatis erectis et per plures 
annos persistentibus. Folia coriacea, aromatica, ovalia, obtusa et 
mucronulata, basi late cuneata, 8-15 mm. longa et 5-8 mm. lata, 
margine revoluta, supra initio lepidota, mox glabra, atroviridia, leviter 
rugulosa, subtus dense tomento sublepidota fusco-ferrugineo, initio 
flavido obtecta, costa media supra impressa subtus elevata, nervis 
secundariis obsoletis; petioli 2-4 mm. longi, lepidoti. Flores 6-12, ter- 
minales, umbellato-racemosi; pedicelli 5-7 mm. longi, flavido-lepidoti; 
bracteae pedicellis subaequilongae, oblongae, ciliatae, utrinque pubes- 
centes, partim persistentes, calyx conspicuus, membranaceus, viridi- 
flavus, lobis 5 oblongo-obovatis 3-4 mm. longis 1-1.5 cm. latis 
rotundatis sursum ciliatis extus lepidotis intus puberulis; corolla hypo- 
crateriformis, albida v. pallide lutea, extus lepidota et sparse pubescens, 
tubo cylindrico 6-7 mm. longo intus villoso praesertim faucem versus, 
subito in limbum erecto-patentem ampliatum, lobis suborbicularibus 
4-6 mm. longis et 5-7 mm. latis; stamina 5, plerumque tubo paullo 
breviora, filamentis circiter 4 mm. longis basi dilatatis glabris, antheris 
ovoideis ochraceis; ovarium subglobosum, circiter 1 mm. longum, 
dense flavido-lepidotum; stylus staminibus paullo brevior, glaber, 
sursum incrassatus, stigmate capitato. Capsula subglobosa, circiter 
4 mm. longa, lepidota, 5-valvata, stylo persistente, basi calyce per- 
sistente suffulta; semina flavido-brunnea, nitida, ovoidea, 1 mm. 
longa, utrinque acuta, fere exalata. 
Western Szech'uan: Mupin, growing on exposed rocks, alt. 
3000-3600 m., June and October 1908 (Nos. 1208, type, 3454 
same locality, alt. 4000—4300 m., October 1910 (No. 4237); Wa- 
shan, cliffs, 3300 m., July 1903 (Veitch Exped. No. 3933); without 
precise locality, October 1904 (Veitch Exped. No. 3931 and 
No. 1888). 
This new species belongs to a small group which includes R. anthopogon D 
R. anthopogonoides Maximowiez, R. rufescens Franchet, R. cephalanthum, "fh 
chet and two or three other species from all of which it is readily - pale 
its lepidote corolla. All the species are very closely allied, having white oF 
yellow flowers and are all strictly alpine plants. In this new species the pn 
pedicels and shorter bracts render the calyx more clearly visible than it is in 9 
species. 
