CISTINEZ. 47 
2. HELIANTHEMUM. 
Helianthemum, Pers. Syst. ii. p. 75 ; Benth. et Hook. Gen. Plant. i. p. 118. 
Herbs or under-shrubs. Nearly 150 forms have been described as species; but these 
Bentham and Hooker would reduce to about thirty, whereof six or more are natives of 
North and Central America, one (or three?) of South America, and nearly all the others 
of the Mediterranean region, a few extending to other parts of Europe and Western 
Asia. 
1. Helianthemum arenicola, Chapm. Fl. S. U. States, p. 35. 
FLoripa.—Mexico, Zimapan (Coulter, 743), Chinantla (Ziebmann). Hb. Kew. 
2. Helianthemum argenteum, Hemsley, Diag. Pl. Nov. pars alt. p. 20. 
Fruticosum nanum dense ramosum, ramis tenuibus sinuosis, foliis parvis alternis argenteo-pubescen- 
tibus lineari-lanceolatis crassiusculis confertis vix patentibus, floribus dimorphis vel fortasse 
trimorphis longiuscule pedicellatis vel fere sessilibus. 
Frutex dense et tortuose ramosus, 3-4 poll. altus, ramis tenuibus sinuosis. Folia alterna, conferta, 
vix patentia, lineari-lanceolata, 2-3 lin. longa, semilineam lata, mucronata, utrinque argenteo- 
pubescentia, crassiuscula. Flores dimorphi vel fortasse trimorphi, perfecti non visi, longiuscule 
pedicellati vel fere sessiles, apetali vel petaliferi, petaliferis imperfectis, circiter 6 lin. diametro ; 
sepala persistentia, argenteo-pubescentia; petala flava aut nulla aut 3 vel 4 in spec. nostris, 
obovata, interdum 1 vel 2 eorum inzqualiter biloba, 24 lin. longa; stamina circiter 12, fila- 
mentis sursum leviter dilatatis ; ovarium glabrum, circiter 8-10-ovulatum. Capsula imma- 
tura trisperma, seminibus deltoideis. 
Nortu Mexico, region of San Luis Potosi, 6000 to 8000 feet (Parry & Palmer, 29). 
Hb. Kew. 
3. Helianthemum astylum, Mog. et Sessé in DC. Prodr. i. p. 284. 
Mexico (Mogino). | 
This was probably founded upon one of the states of H. glomeratum. - 
4. Helianthemum canadense, Michx. Fl. Am. Bor. i. p. 308% 
SoutH Mexico, Llanos de Perote, Vera Cruz (Schiede & Deppe). 
This is on the authority of Schlechtendal, and it is most likely H. glomeratum. 
True H. canadense ranges, according to Chapman (‘Flora of the Southern United 
States,’ p. 36), from Florida northward to Canada. 
5. Helianthemum glomeratum, Lag. DC. Prodr. i. p. 269. 
Cistus glomeratus, Lag. Gen. et Sp. p. 16. 
-Helianthemum polifolium, Hook. et Arn., non A. Gray. 
Heteromeris mexicana, Spach. 
Lechea mexicana, Walp. 
Teniostema micranthum, Spach. 
Norra Mexico, region of San Luis Potosi, 6000 to 8000 feet (Parry & Palmer, 28), 
Sierra Madre (Seemann, 2143), Tepic (Barclay); Sour Mexico, valley of Mexico 
