100 CISTACE^E. 



direction opposite to that of the sepals. Stamens indefinite, distinct, 

 hypogynous ; filaments slender ; anthers innate. Ovary distinct, 1- to 

 many-celled, few- or many-ovuled, the ovules with a foramen at their apex ; 

 style single or none ; stigma simple. Fruit a capsule, usually 3- or 5-valved, 

 occasionally 10-valved, either 1-celled or imperfectly 5- to 10-celled. 



Leaves simple, usually entire, the lower opposite, the upper alternate, 

 stipulate or exstipulate. 



A small and unimportant order, comprising in North America three 

 genera, namely, Helianthemum, Hudsonia, and Lechea, the first-named 

 only being represented by medicinal species. 



HELIANTHEMUM.— Rock Rose. 



Character of the Genus. — Sepals and petals as in the character of the 

 order. Ovary 1-celled ; style short or none. Most North American species 

 bear two crops of flowers, of widely different aspect. The early flowers are 

 few in number, solitary or in terminal corymbs, have large yellow petals, 

 and produce many-seeded capsules, while the later ones are in axillary 

 clusters, the petals small and inconspicuous or absent altogether, and the 

 capsules few-seeded. 



Helianthemum Canadense Michaux. — Frostiveed, Rock Rose. 



Description. — Calyx : sepals 5, the outer two small. Corolla : petals of 

 the early flowers 5, large and showy, opening, but once, in sunshine, and 

 falling the next day. Expanded flower about 1 inch broad. 



Stem erect, hairy, pubescent, 6 to 18 inches high, at first simple, ulti- 

 mately branching. Leaves alternate, entire, lanceolate-oblong, pubescent, 

 about 1 inch long. Early flowers solitary ; secondary flowers in axillary 

 clusters. Period of flowering, June to August. 



Habitat. — In dry, sandy soil from Canada southward ; common. 



Helianthemum corymbosum Michaux. 



Description^ — Like the preceding, except that the flowers are in terminal 

 corymbs, the showy ones becoming stalked, while the others are sessile, 

 and the whole plant being more pubescent. 



Habitat. — In pine barrens from New Jersey to Florida, along the coast. 



Part Used. — The herb — not official. 



Constituents. — The only constituent of therapeutic activity thus far dis- 

 covered in these plants is tannin. 



Preparations. — There are various commercial preparations. 



Medical Properties and Uses. — Frostweed is a mild astringent, aud prob- 

 ably nothing more, though it is not without advocates among those who 

 appear to think every plant must, of necessity, possess therapeutic virtues. 

 Of course such persons value it highly in scrofula, etc. 



