178 



FAMILIES OF FLOWERING PLANTS 



Family Dipterocarpaceae. Wing-fruit family. Contains 16 genera 

 and over 300 species, natives exclusivelj'^ of the Asiatic tropics. They 

 are trees of lofty proportions, resembling the Guttiferae in the abund- 

 ance of resinous juice which they contain. The flowers are distin- 

 guished by the calyx, which is di\aded into five unequal sepals, two of 

 them very large and wing-Kke. The whole calyx forms a persistent 

 crown on the fruit, which is of woody texture, 1-celled and 1-seeded. 

 The resin of various species is used as a medicine and also as an illu- 

 minant. Fig. 158 gives a good idea of the peculiar fruit. 



Family Elatinaceae. Water-wort family. This group of marsh or 

 aquatic herbs consists of two genera, Elatine and Bergia, wirli about 25 

 species of wide distribution. They have opposite or whorled leaves, 



with small regular flowers having 

 2-5 sejoals, 2-5 petals, as many or 

 twice as many stamens, and a 2-5- 

 celled ovary becoming capsular in 

 fruit. 



Family Frankeniaceae. Fran- 

 kenia Family. Four genera and 

 about 15 species of maritime under- 

 shrubs of heath-like aspect, widely 

 distributed in tropical or subtrop- 

 ical regions. Frankenia is repre- 

 sented by a species on the coast of 

 southern California. The capsule 

 dift'ers from that in related families 

 by being one-celled. 



Family Tamaricaceae. Tam- 

 arisk Family. Contains 4 genera 

 and about 40 species, trees or 

 shrubs of wide distribution, with 

 small alternate leaves and white or 

 pink solitary or clustered flowers. 

 The ovary is of rather unusual structure, being imperfectly 3-celled h\ 

 the intrusion of 3 placentas or partitions. The seeds bear tufts of hairs. 

 Tamarix, the tamarisk of Europe, represented by several species, 

 is a graceful small tree with handsome racemes of pink flowers. 3Iyri- 

 caria, a closely related genus, occurs in northern Europe and Asia. 

 Becuimnria, a genus of low undershrubs, is found in the Mediterranean 

 region and in central Asia (see Fig. 159). 



Family Fouquieriaceae. Candle-tree Family. Contains the single 

 genus Fonquiera with about 5 species, natives of Mexico and the South- 

 west. F. splevdens, the "ocotilla" of the Mexicans, is a beautiful tree 



Fig. i6o. Woollj' Hudsonia {Hudsonia tomen- 

 tosa). After Britton and Browu, 111. Fl. North- 

 ea.st, U. S. 



