248 JOURNAL OF THE ARNOLD ARBORETUM [vol. iv 



indicate that De Candolle as well as Bosc had in mind the hybrid between 

 T. cordata and T. platyphyllos described the same year as T. vulgaris 

 Hayne (T. hybrida Bechstein, a form or synonym of T. vulgaris, was 

 first described and figured by Bechstein in 1819 in his Forstbot. ed. 3, 

 1463, tab. 4, not in 1810 as quoted by Schneider, and not by Behlen in 

 ed. 5 as quoted in Index Kewensis), but the description of the under side 

 of the leaves, the petioles and the branchlets as "pilosiuscula" and of the 

 bark of the branches as red may be taken to indicate that the authors had 

 before them a form of T. platyphyllos and probably the var. rubra. Bosc 

 himself in 1821 refers his "Tilleul de Corinthe" to T. corallina (in Encycl. 

 M6th. Agric. vn. 748) and Spach (in Ann. Sci. Nat. s6r. 2, n. 337 [1834]) 

 refers both names as synonyms to his T. mollis ( = T. platyphyllos). In 

 1825 De Candolle gives "Tauria" as the habitat of T. rubra and cites a 

 specimen collected by Steven without changing the description from that 

 of 1813. This is not identical with T. rubra of Simonkai and of later 

 authors which I refer to T. dasystyla Stev. (T. begoniifolia Stev., T. 

 multiflora Ledeb., T. caucasica Rupr.), nor is it the T. corinthiaca of 

 Simonkai (in Mat. Term. Kozl. Mag. Tud. Akad. xxn. 330 [1888] ); the 

 characters of these two species do not agree with the descriptions given 

 by Bosc and De Candolle and it is very unlikely that any of them were 

 in cultivation at that time, while Bosc states that his "Tilleul de Corinthe" 

 has been in cultivation since time immemorial. In regard to T. corinthiaca 

 Bosc it should be stated that the name did not originate with Bosc who 

 calls it "Tilleul de Corinthe" (in Nouv. Cours Agric. xu. 139 [1809] and 

 in ed. 2. XX in. 406 [1823|). Who first latinized Bosc's name I cannot say 

 with certainty; I find it first mentioned by De Candolle in 1824 (Prodr. I. 

 513) as a synonym of his T. rubra for which he gives " Tauria" as the 

 native country. This would leave without a name the form occurring in 

 Greece and distinguished by Simonkai as T. corinthiaca Bosc, but I 

 doubt if it is specifically distinct from T. dasystyla Stev. 



Helianthemum nummularium var. cupreum Schneid. f . crocatum, comb. 



nov. 



H. hyssopifolium a. crocatum Sweet, Cist. 29, t. (1825-30). 



H. chamaecistus var. q. cupreum Grosser in Engler, Pflanzenr. iv-193, 84 



(1903), in part, as to synon. a. crocatum. 

 H. vulgare var. crocatum Bean, Trees & Shrubs Brit. Isl. i. 617 (1914). 



This form differs from var. cupreum only in its saffron-yellow flowers 

 more or less suffused with a ferrugineus or coppery tint. 



As Janchen has shown (in Oesterr. Bot. Zeitschr. lviii. 406-413 [1908]) 

 the correct name according to the International Rules of the Sun Rose 

 usually called Helianthemum chamaecistus Mill, or H. vulgare Gaertn. is 

 H. nummularium Mill, based on Cistus nummularius L. Janchen, however, 

 distinguishes besides //. nummularium the following species: H. hirsutum 

 Merat, H. nitidum Clementi, H. tomentosum Spreng. and H. grandijiorum 

 Lam. & DC. which all seem to be connected by intermediate forms and 

 are best considered varieties or subspecies of H . nummularium. Most of 



