N. ORD.—CISTACE Ae 28 
GENUS.—HELIANTHEMU M ,* TOURN. 
SEX. SYST.—POLYANDRIA MONOGYNIA. 
OC hs F-US. 
ROCK ROSE. 
SYN.— HELIANTHEMUM CANADENSE, MICHX.: H. RAMULIFLORUM, 
MICHX.; H. ROSMARINIFOLIUM, PURSH.; H. CORYMBOSUM, PURSH.; 
CISTUS CANADENSIS, LINN.; C. RAMULIFLORUM, POIR.; LECHEA 
sans say LINN; HETERAMERIS CANADENSIS, SPACH.; H. MICHAUXII, 
COM. NAMES.—ROCK ROSE,+ FROST-WORT, FROST-PLANT. FROST- 
WEED, HOLLY ROSE; (FR.) HELIANTHEME DU CANADA; (GER.) 
CANADISCHES SONNENROSCHEN. 
A TINCTURE OF THE WHOLE PLANT HELIANTHEMUM CANADENSE, MICHX, 
Description.—This peculiar plant grows to a height of from 6 to 12 inches. 
Stem at first simple, erect or ascending, somewhat hairy ; pubescence stellate and 
fasciculate. Leaves sessile or nearly so, oblong lanceolate. Flowers of two sorts, 
both diurnal; Primary form: few or solitary, large, pedunculate; ca/yx hairy 
pubescent; Aefals 5, obovate, fugacious, crumpled in the bud, erosely marginate ; 
stamens indefinitely numerous; fod ovate, shining, many-seeded ; Secondary form: 
numerous, small, sessile, axillary, solitary or few-clustered upon short leafy branches; 
sepals 5, the outer pair sometimes wanting ; petals very small or absent; stamens 
3 to 10; fod minute, hoary, 3- few-seeded. Sty/e columnar or absent: stigma 
capitate, 3-lobed, fimbriolate. ruta 1-celled, 3-valved capsule. Seed somewhat 
triangular; esta rough; eméryo incurved in the form of a hook or ring. 
There are two very distinct forms of this species, differentiable as follows: 
EarLy FLOWERING ForM (Fic. 1). LATER FLOWERING Form (Fic. 2). 
Stems upright, branching, bright crimson, nearly | Stem upright, less branched, purplish, covered 
glaucous. with a downy pubescence. 
Leaves ovate-lanceolate, light green. Leaves dark green. 
Primary flowers axillary solitary. Primary flowers terminal clustered. 
Secondary flower-buds minute, Secondary flowers numerous, larger. 
Capsule of primary flowers nearly twice as large | Capsule of pri mary flowers smaller. 
as the later form. 
Cistaceze.—This small family of low shrubs or herbs is represented in North 
America by 3 genera and 17 species; its members are characterized as follows : 
* "Hios, hedios, the sun; dvéenov, anthemon, a flower, 
+ The true Rock Rose is C. Creticus, Linn., a native of Syria. 
