FAMILIES OF FLOWERING PLANTS 



185 



Piriqueta Caroliniana is a common plant of the Florida pine bar- 

 rens, and resembles a rock-rose {Helianthemum) when its yellow flow- 

 ers are expanded in the sunlight (see Fig. 164), The drug known as 

 damiana is derived from a Mexican species of Turnera ( T. aphrodisiaca) 

 and also from the West Indian T. diffusa. 



Family Malesherbiaceae. Crown wort Family. Consists of the 

 single genus Malesherhia, with about 15 species, natives of Peru and 

 adjacent countries on the west coast of South America. They are 

 herbs or low shrubs with alternate leaves and solitary yellow or blue 

 flowers. The calyx is tubular, and merely 5-lobed, being gamosepalous 



Fig. 165. Flower and leaf of Passiflora foetida, showing the corona, and the finely dissected 

 bracts surrounding the flower. Original. 



(not divided into distinct sepals). The petals are 5, persistent; sta- 

 mens 5-10, their filaments often connected with the 3 styles, forming a 

 column; ovary borne on a stalk, 1-celled; frait a 3-valved capsule. 

 These plants are closely allied to the true passion-flowers, and were 

 formerly included in the same family. 



Family Passifloraceae. Passion-flower Family. Contains 15 gen- 

 era and about 300 species, of wide distribution, mostly in tropical 

 regions. Of these, Passiflora, with about 250 species, is by far the 

 most important. The plants are herbs or shrubs, often climbing, 

 with alternate leaves and mostly solitary flowers. The calyx is 

 5-lobed; the petals 5, frequently clothed on their upper surfaces 

 with small processes or filaments; stamens 5, monadelphous; 



