328 ARBORETUM AND FRUTICETUM. PART HI. 



with flowers every year. In the London nurseries, where this species is 

 generally called C. ladaniferus, or by its English name of gum cistus, 

 plants are from 1*. to 1*. 6d. each. 

 Sfc 35. C. LADAN!FERUS L. The Ladanum-bearing Gum Cistus, or Rock Rose. 



Identification. Lin. Sp., 737. ; Don's Mill., 1. p. 300. 



Synonymes. Ciste ladanifere, Fr. ; Ladanum Cisten Rose, Ger. 



f'ariciies. C. 1. I. albifldrus Dec. Prod., i. p. 266., Swt. Cist, t. 94. ; Ledon, i., Clus. Hist., i. p. 78. ic. ; 



and C. /. 2 maculdtus Dec. Prod., I c., Swt. Cist., C. J. 3 plenifblius Ait. Hart. Kew., iii. p. 305., 



are varieties of this species. 



Spec. Char., $c. Leaves almost sessile, connate at the base, linear-lanceolate, 

 3-nerved, upper surface glabrous, under surface tomentose. Capsule 10- 

 celled. Petals imbricate. (Don's Mill., i. p. 301.) A shrub 4 ft. high, a 

 native of Spain and Portugal, upon hills ; introduced into England in 1629, 

 and producing large white flowers in June and July. The leaves are lance- 

 olate, and nearly sessile, of a deep green; the flowers terminating the 

 branches, solitary, white, and large ; each flower being from H in. to 2 in. 

 broad. The plant requires a little protection during winter, and was to be 

 had in Colvill s Nursery in 1826. This species, as well as C. Ledon and 

 C. creticus, and doubtless various others, produces the resinous exudation 

 known as gum ladanum, the mode of gathering which is described in p. 320. 



b. Stigma capitate, small. Style cylindrical, equalling the Stamens in Length, 

 a. 36 C. CLU V SI/ Dunal. Clusius's Cistus, or Rock Rose. 



Identification. Dunal. ined., Dec. Prod., 1. p. 266. ; Swt. Cist., 32. ; Don's Mill., 1. p. 301. 

 Syntmymcs. Cfstus Libanbtis & Lam. Diet.. 2. p. 18.. Desf. Atl., 1. p. 412. : C. undulatus Link ; 



Ledon, vii., Clus. Hist., 1. p. 80. ic. 

 Engraving. Swt. Cist., t. 32. 



Spec. Char., $c. Erect. Leaves somewhat 3-nerved, linear, with revolute 

 margins, under surface canescent. Flowers somewhat capitate. Calyx 

 3 5-sepaled, pilose. Sepals ovate, acute. Capsules 5-celled. (Don's Mill., i. 

 p. 301.) A shrub 2 ft. high, from Spain and Barbary, in 1810. The leaves 

 and flowers are smaller than those of any of the other sorts here described. 

 The plant forms a handsome and compact bush, and stands the winter well 

 in a dry situation. It approaches the nearest to C. monspeliensis. Plants 

 were in the Fulham Nursery in 1826. 



GENUS II. 



HELIA'NTHEMUM. THE HELIANTHEMUM, or SUN ROSE. Lin. Syst. 

 Polyandria Monogynia. 



Identification. Tourn. Inst, 248. t. 128. ; Gffirt. Fr., 1. p. 371. t. 76. } Dec. Fl. Fr., 4. p. 815. ; Prod., 

 1. p. 260. ; Don's Mill., 1. p. 301. 



Synonymes. 6'fsti species of Lin. ; Heliantheme Sonnen Gurtel, Ger. 



Derivation. From helios, the sun, and anthemon, a flower ; because the flowers open with the rising 

 of the sun in the morning, and the petals fall off with the setting of the sun in the evening. The 

 flowers of Heli&nthemum, as well as of Cistus, only last for a few hours when the sun shines ; 

 and if the weather is dull, and the sun does not make its appearance, the flowers do not open, but 

 remain unexpanded. Should this continue for several days together, they will decay in the bud. 



Gen. Char. Calyx of 3 5 sepals; when 3, these are equal, and disposed in a 

 single series ; but, when 5, they are unequal, and disposed in a double one; 

 the two outer sepals are usually smaller than the inner ones, very rarely 

 larger. Petals 5, usually regularly denticulated at the top. Stigma 

 capitate. Style sometimes almost wanting, sometimes straight, sometimes 

 oblique, and sometimes bent at the base. Ovary triquetrous. Capsule 

 3-valved; valves with a narrow dissepiment, or a seminiferous nerve 

 in the middle of each. Seeds angular, smooth. Albumen mealy. 

 Embryo uncinately indexed Erect or trailing herbs, subshrubs, or 

 shrubs. Leaves opposite and alternate, with or without stipules, 3-nerved 

 or feather-nerved. Pedicels usually furnished with bracteas at the base 



