1923] REHDER, NEW SPECIES, VARIETIES AND COMBINATIONS 249 



the resulting new combinations have been already made by C. Schneider 

 (111. Handb. Laubholzk. n. 351-352, 1909), but a few forms not unfre- 

 quently met with in gardens, as the one cited above and the following, 

 were not mentioned by him. 



Helianthemum nummularium var. mutabile, comb, no v. 



Cistus mutabilis Jacquin, Misc. n. 340 (1781); Icon. PL Rar. i. 10, t. 99 



(1781-86). 

 Helianthemum mutabile Persoon, Syn. n. 79 (1807). — Guimpel, Otto & Hayne, 



Abb. Fremd. Holzart. 56, t. 46 (1819-1825).— Sweet, Cist. 106, t (1825-30). 

 H. vulgare var. e. mutabile Willkomm, Icon. Descript. PL n. 116 (1856). 

 H. chamaecistus var. e. mutabile Grosser in Engler, Pflanzenr. iv-163, 86 (1903). 



This variety has the leaves sparingly pilose above or nearly glabrous 

 and gray-tomentose beneath. The sepals are reddish and villose on the 

 ribs and glabrous between them; the petals are pale rose or sometimes 

 variegated with white. 



Helianthemum nummularium var. stramineum, comb. nov. 



//. stramineum Sweet, Cist. 93, t. (1825-30). 



H. chamaecistus var. £. stramineum Grosser in Engler, Pflanzenr. iv-163, 86 



(1903). 

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



This variety has the leaves green and pilose above, whitish tomentose 

 beneath, flat or scarcely revolute at the margins; the sepals are nearly 

 glabrous and the petals sulphur-yellow with a darker yellow blotch at base. 



Helianthemum nummularium var. venustum, comb. nov. 



H. venustum Sweet, Cist. 10, t. (1825-30). 



H. mutabile var. canescens (Sweet) K. Koch, Hort. Dendr. 37 (1853), in part. 

 H. chamaecistus var. 5. venustum Grosser in Engler, Pflanzenr. iv-163, 86(1903). 

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



This variety has purplish branchlets and the leaves glabrescent and 

 lustrous above, whitish tomentose beneath; the sepals are stellate-puber- 

 ulous, the petals rather large and crimson with a yellow blotch at base. 



Helianthemum nummularium var. diversifolium, comb. nov. 



H. diversifolium Sweet, Cist. 95, t. (1825-30). 

 H. mutabile Pers. y. diversifolium K. Koch. Hort. Dendr. 37 (1853). 

 H. chamaecistus var. *). diversifolium Grosser in Engler, Pflanzenr. iv-163, 

 86 (1903). 



This variety has the leaves hirsute above and whitish tomentose beneath, 

 the upper ones linear-lanceolate, acute and revolute at the margin, the 

 lower ones oval, obtuse and flat. The sepals are pilose, and the petals 

 are red with a darker blotch at the base. 



Helianthemum nummularium var. diversifolium f. rubro-plenum, 



nom. nov. 



H. diversifolium /3. multiplex Sweet, Cist. 98, t. (1825-30). 

 H. mutabile 5. multiplex K. Koch, Hort. Dendr. 37 (1853). 

 H. vulgare var. diversifolium multiplex Bean, Trees & Shrubs Brit. Isl. i. 617 

 (1914), not if. nummularium var. tomentosum f. multiplex Schneid. 



This is a form with double flowers of the preceding variety. 



