34 CISTACE^. 



Stamens 6, united around the torus, free at the apex. Pod 

 stiped. 



G. pentaphylla D. C. : smoothish ; leaves quinate ; the lower and floral 

 ones ternate ; leafets entire and*subserrulate. Cleame pentaphylla Linn. 



In cultivated grounds. Penn. to Flor. July. 0. Stem 2 feet high, viscid. 

 Flowers white, in long terminal racemes. Petals obovate, with very long capil- 

 lary claws. Pod long, linear, on a long foot-stalk. Five-leaved Gynandropsis. 



2. POLANISIA. /?«/.— Polanisia. 



(From the Greek iroXv, much, and aviaoi, unequal ; in allusion to the inequality 

 of the stamens.) 



Calyx of 4 sepals, spreading. Petals 4. Stamens 8 — 32. 

 Disk small. Pod sessile or scarcely stiped. Style distinct. 



P. graveolens Raf. : viscidly pubescent ; leaves ternate ; leafets elliptical- 

 oblong ; stamens & — 12 ; pod oblong, attenuate at base, muricate with a 

 glandular pubescence. Cleovie dodecandra, var. Canadensis Linn. 



Gravelly banks of rivers and lakes. Can. to Penn. W. to Miss. : rare. June 

 — Aug. %. — Stem. 6 — 15 inches high, often purplish. Flowers in a corymbose 

 raceme, yellowish- white and purple. Whole plant more or less viscid and fetid. 



Strong-scented Polanisia. 



Order XIV. CISTACE^.-^Rock Roses. 



Sepals 5, persistent, unequal, the three inner often with a 

 twisted aestivation. Petals 5, (very rarely 3,) very fugitive, 

 crumpled in aestivation and twisted in a direction contrary to 

 that of the sepals. Stamens definite or indefinite ; ovary 1 or 

 many-celled ; style and stigma simple, hypogynous ; style sin- 

 gle. Fruit capsular, either 1 -celled with parietal placentae in 

 the axis of the valves, or imperfectly 5 — 10-celled, Seeds few 

 or numerous. Embryo inverted, either spiral or curved in the 

 midst of mealy albumen. — Shrubs or herbaceous plants. Leaves 

 usually entire, opposite or alternate. Flowers very fugacious. 



1. HELIANTHEMUM. Tourn.— Rock Rose. 



(From the Greek ^Xios, the sun, and avdcfiov, 2i flower ; the flowers opening only 

 in sunshine.) 



Calyx with 3 equal sepals, or 5 disposed in two rows, the 

 two outer ones often smaller, rarely larger. Petals 5, (some- 

 times wanting,) often, irregularly denticulate at the apex. Stig- 

 ma capitate. Ovary triquetrous. Capsule 3-valved, with the 

 dissepiment in the middle of the valves. Seeds angled, smooth. 



1. H. Canadense Mich. : stem at first simple, erector ascending; leaves 

 oblong or somewhat lanceolate, with revolute margins, (when dry,) and with 



