34 CISTACE^E. 



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. Cleome pentaphylla Linn. 



In cultivated grounds. Penn. to Flor. July. (I). 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. Raf. Polanisia. 



(From the Greek n-oXv, much, and aviaos, 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 8 12 ; pod oblong, attenuate at base, muricate with a 

 glandular pubescence. Cleome 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 XIY. CISTACE^E. ROCK ROSES. 



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

 twisted aestivation. Petals 6, (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 fi\ios, the sun, and avBefJiov, a 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 



