134 THE AZALEAS OF NORTH AMERICA 



Of Michaux's specimens of var. a. flammeum collected according to his Journal near 

 Two-Sisters Ferry, Georgia, on April 27, 1787, and of his specimens of yar. 0. cro- 

 ceum I have photographs before me which show that the latter variety is R. calen- 

 dvlaceum, while a. flammeum differs chiefly in its slenderer corolla-tube distinctly 

 longer than the limb and not conspicuously glandular-hairy and in the smaller 

 corolla-lobes and thus agrees with the plant here called R. speriosum. 



Rhododendron speriosum has been usually confused with R. calendulaceum, and 

 particularly with the scarlet-flowered form of it, from which it may be chiefly dis- 

 tinguished by the slenderer corolla-tube more abruptly enlarged at the apex into 

 the limb and longer than the limb, by the absence of glandular hairs on the 

 corolla-tube which is covered with a short villous pubescence interspersed with 

 pilose hairs and by the generally smaller and comparatively broader leaves. The 

 color of the flowers is always scarlet or bright red and never varies to yellow, as 

 it does in R. calendulaceum and the flowers are more numerous in each inflorescence. 

 It shows little variation except in shape and size of sepals, which may be oblong 

 and up to 3 mm. long or nearly obsolete, and in the shape and size of the capsules. 

 Geographically the two species are well separated; R. calendulaceum is essentially 

 an Alleghanian plant, while R. speriosum belongs to the Piedmont region of Geor- 

 gia, but in northern Georgia the ranges of the two species touch and at Thompson's 

 Mill, Gwinnett County, both species have been collected by H. A. AUard. 



Though the species was well known in cultivation at the beginning of the last 

 century, it later almost disappeared from the gardens until it was reintroduced in 

 1916 through the Arnold Arboretum, though in 1881 it was still cultivated at 

 Kew as Azalea cocrinea major according to a specimen before me. There is also 

 in the herbarium of the Arnold Arboretum a specimen collected by H. Zabel in 

 the Botanic Garden at Muenden, Hanover, from a plant received as Azalea coccinea 

 from Booth's nursery at Flottbeck near Hamburg in 1872. It is certainly as hand- 

 some as R. calendulaceum, but probably more tender and not suited for cultivation 

 in the open ground in the North. 



Rhododendron nudiflorum, Torrey, FZ. U. S. 424 (1824) ; Fl. N. F.I. 

 438 (1843). — Gray, Syn. Fl. II. 1, 41 (1878). — J. Robinson, Fl. 

 Essex Co. Mass. 73 (1880). — Dame & Collins, Fl. Middlesex Co. Mass. 

 63 (1888).— Britton, Cat. PI. N. Jersey, 162 (1889). — Dippel, 

 Handb. Laubholzk. I. 414, fig. 267 (1889). — Coulter & Watson, 

 Gray's Man. ed. 6, 320 (1890).— Dudley & Thurston, Cat. PI. Lacka- 

 wanna & Wyoming Valleys, 38 (1892). — Beckwith & Macauley, PI. 

 Monroe Co. N. Y. 83 (in Proc. Rochester Acad. Sci. Ill) (1894), in 

 part. — Deane in Rhodora, I. 94 (1899); III. 196 (1901). — Robinson 

 & Fernald, Gray's New Man. 631 (1908). —Graves & others, Cat. 

 Flow. PI. Conn. 308 (1910). — Schneider, III. Handb. Laubholzk. 502, 

 fig. 329 s-t (1911). 



Azalea lutea Linnaeus Spec. I. 150 (1753), excluding the synonyms of Colden 

 and Gronovius. 



Azalea nudiflora Linnaeus, Spec. ed. 2, 214 (1762), excluding the synonyms of 

 Colden and Gronovius. — Wangenheim, Beytr. Forstwiss. 67 (1787). — 

 Willdenow, Spec. I. pt. 2, 831 (1798).— Eaton, Man. Bot. ed. 2, 165 (1818).— 

 Elliot, Sketch Bot. I. 241 (1821), in part. — Bigelow, Fl. Boston, ed. 2, 82 



