Rhododendron. ERICACEAE. 41 



t. 24. Swamps, Canada and Maine to Florida and Arkansas. Runs into manifold vari- 

 eties ; the following being those most marked : 



Var. glaucum. Leaves glaucous-whitened beneath, dull and sometimes glaucous 

 above also. Azalea viscosa, var. glauca, Michx. 1. c. A. glauca, Lam. 111. t. 110. R. glau- 

 cum, Don, 1. c. Form more strigose-hispid is A. hispida, Pursh, 1. c. (R. hispidum, Torr. 1. c.) 

 A. scabra, Loddiges, &c. New England to Virginia. 



Var. nitidum. Leaves oblanceolate, brighter green both sides : stems a foot to a 

 yard high. /?, nitidum, Torr. 1. c. Azalea nitida, Pursh, 1. c. ; Lindl. Bot. Reg. t. 414. 

 Mountains, New York to Virginia. 



.H. ++ Flowers earlier and less fragrant, preceding or accompanying the leaves ; these soft-pnbo- 

 cent beneath and more membranaceous, 1 to 3 inches long; the midrib and the branchlets either 

 slightly or not at all chaffy-strigose or hispid: calyx usually very small. 



R. nudiflorum, Torr. 1. c. Corolla from light rose-color or flesh-color to rose-purple; 

 the viscid tube as long as or rather longer than the limb. Azalea nudiflora, L. Spec, 

 ed. 2, 214; Sims, Bot. Mag. t. 180; Emerson, 1. c. t. 24. A. hitea, L. Spec. ed. 1. A. peri- 

 dymenoides & A. canescens, Michx. 1. c. A. bicolor, Pursh, 1. c. Rhododendron canescens, bicolor, 

 &c., Don, 1. c. Swamps, low grounds, or shaded hillsides, Canada to Florida and Texas. 

 Varying much in color, &c., at the south sometimes passing into yellow. Many hybrid 

 forms are in cultivation. 



R. calendulaceum, Torr. 1. c. Corolla from orange-yellow to flame-red ; the tube 

 mostly hirsute-glandular, shorter than the ample limb: mature leaves more tomentose 

 beneath. Azalea calendulacea, Michx. Fl. i. 151; Pursh, I.e.; Bot. Mag. t. 1721, 2143. - 

 Woods in the Alleghany Mountains, from Pennsylvania to Georgia, extending southward 

 into the middle country. 



# * Strobilaceous flower-buds of fewer and early caducous scales: corolla irregular, with a short 

 or hardly any tube, anteriorly divided to the base; the limb equalling the 10 stamens and style. 

 lihudora, Duhamel, in Linn. Gen. 



R. Rhodora, Don. A foot or two high, the young parts sparingly strigose-hairy : 

 flowers somewhat preceding the leaves, short-pcdicelled : calyx very small : corolla less 

 than an inch long, purplish-rose-color, bilabiately parted or divided; the posterior lip 

 3-lobed ; the anterior of two oblong-linear and recurving nearly or quite distinct petals : 

 leaves oblong, pale, glaucescent, more or less pubescent. Syst. iii. 848 ; Maxim. 1. c. 

 Rhodora Canadensls, L. ; L'Her. Stirp. i. 101, t. 08 ; Lam. 111. t. 304; Bot. Mag. t. 474; 

 Duham. Arb. ed. nov. iii. 53; Emerson, I.e. t. 25. Rftodora congesta, Mcench. Rhodo- 

 dendron pulcliellum, Salisb. Cool bogs, New England to mountains of Pennsylvania and 

 northward to Newfoundland : fl. May. Mature leaves 1 to 2 inches long, glandular- 

 mucronulate. Flowers rarely white, sometimes variably or variously cleft or divided, or 

 the lower petals more united to the upper lip. 



4. EURHOUODENDRON. Inflorescence terminal ; the umbellate or somewhat 

 corymbose flowers from a separate strobilaceous bud (of mostly numerous and 

 well-imbricated caducous scales), terminating the growth of the previous year; 

 the leaf-buds lateral and below : leaves coriaceous and persistent : calyx various, 

 usually small or minute : corolla mostly 5-lobed and little irregular : stamens 

 (commonly 10) and style rarely exserted, somewhat declined, or sometimes equally 

 spreading: flowers mostly large and showy, in early summer. -- Eurhododendron 

 & Osmothamnus (DC.), Maxim. 1. c. 



# Not lepidote, glabrous or soon becoming so: the pubescence of young parts (if any) scurfy- 

 tomentose and deciduous: leaves ample and thick-coriaceous: steins and branches stout and 

 erect: flowers many in the cluster, mostly developing earlier than the leaf-buds: seeds scobiform 

 or scarious-appendaged at one or both ends. 



4 Pacific species : pedicels wholly glabrous : calyx lobes very short and rounded. 

 R. Calif ornicum, Hook. Shrub 3 to 8 feet high, glabrous : leaves broadly oblong, 

 3 to inches long, obtuse with a mucronate or short-acuminate point, acute or acutish at 

 base: corolla rose-purple, broadly campanulate (over an inch long); the broad lobes un- 

 dulate: ovary rusty-hirsute. Bot. Mag. t. 4803 ; Gray, Bot. Calif, i. 458. -- Woods, 

 California from Mendocino Co. extending into Oregon (E. Hall). Corolla much resem- 

 bling that of R. Catatcbiense. 



