204 SYSTEMATIC BOTANY. 



Order XII. CISTACEJE (Rock Rose Family]. 



Herbs, or low shrubs. Leaves simple, the lowest commonly 

 opposite. Sepals mostly 5, the 3 inner convolute in prefloration, 

 the 2 outer minute, or wanting. Petals 5, rarely 3, regular, in 

 prefloration usually convolute in a direction contrary to that of 

 the sepals. . Stamens indefinite, hypogynous, distinct. Ovary of 

 3-5 united carpels. Style I. Fruit a I -celled, or imperfectly 

 3~5-celled capsule. Seeds few, or numerous. 



( Petals 3, persistent Lechea. 

 CISTACE^E.- 



( Petals 3-5, fugacious Hclianthemum. 



I. Lechea. Sepals 5 ; 2 outer much smaller. Petals 3, lanceo- 

 late, small. Stamens 3-12. Stigmas 3, nearly sessile Capsule 3- 

 valved, 3-celled. Placentae each i-2-seeded. y. 



1. L. MINOR {Small Pinweed). Stem nearly smooth, very branching ; 

 leaves linear ; often nearly oblong, scattered, sometimes verticillate ; flowers 

 dull purple, in nearly simple racemes, separate, pedicellate ; capsule globose. 

 In dry grounds, 3'-5' high. June-September. 



2. Helianthemum. Petals 5, or rarely 3, sometimes wanting, 

 fugacious. Stamens numerous. Stigmas 3, more or less united. 

 Capsule triangular, 3-valved. ^ 



i> H. CANADENSE (Rock Rose). Stem simple, pubescent ; leaves oblong, 

 entire, usually alternate, acute, paler beneath ; flowers of two kinds, the 

 earlier ones large, few, bright yellow, fugacious, terminal ; petals large, thin, 

 nearly orbicular, emarginate, twice as long as the calyx ; later ones apet- 

 alous, or with very small petals, axillary, sessile, nearly solitary, very small ; 

 capsules smooth, shining ; those of the apetalous flowers very small. June- 

 September. 



Order XIII. POLYGALACE^: (Milk-wort Family). 



Herbs, or somewhat shrubby plants. Leaves simple. Flow- 

 ers perfect, irregular. Sepals 5, distinct, very irregular ; 3 exterior 

 and smaller ; the 2 lateral, interior ones larger, and petaloid. 

 Petals irregular, the anterior one (the keel) larger than the others. 

 Stamens 6-8, hypogynous. Filaments united into a tube, which 

 is split on the upper side. Ovary compound, free from the calyx, 

 consisting of 2 united carpels. 



I. Polygala. Embryo large, with broad cotyledons. Some species 

 bear concealed flowers, near the ground. (T) y 



i. P. VERTICILLATA (Green-flowered Polygala]. Stem erect, branched ; 

 leaves linear, in whorls ; spikes linear, slender ; flowers very small, crested, 



