230 



FAMILIES OF FLOWERING PLANTS 



or occasionally trees, comprised in about 70 genera and 1200 species of 

 wide distribution. They have opposite or whorled, rarely alternate 

 leaves, and perfect but usually irregular flowers, variously clustered. 

 Calyx 4-5-lobed. Corolla bilabiate (2-lipped) or sometimes regular,* with 

 a slender tube and 4-5-cleft upper portion. Stamens 4, one pair longer 

 than the others, or rarely 2 ; ovary superior, 2-4-celled, composed of 2 

 carpels ; fruit dry, consisting of 2-4 nutlets, or fleshy, a 2-4-seeded 

 drupe. 



The verbena of our gardens, belonging to the genus Verbena, is a 

 characteristic plant of this family. Besides the ornamental species of 

 cultivation having the corolla of many colors, there are many wild species 

 of Verbena, known as vervains, which are decidedly weeds, having small, 

 insignificant flowers in long spikes. (See Fig. 199.) Lippia is some- 



FiG. 199. The Blue Vervain ( Verbena hastata). After Britton and Brown, 



111. Fl. Northeast U. S. 



what similar in its characters to Vevbena; it is very widely represented 

 in the tropics, as is also Lantana, familiar to us as a greenhouse shrub. 

 The black mangrove {Avicemiia nitida), common on the Florida Keys, 

 and remarkable for its habit of sending up from the ground short erect 

 roots, is a tree of this family. The so-called " lemon verbena " belongs 

 to the genus Aloysia. The teakwood of East India {Tectona grandis) is 

 one of the most important Oriental timber trees. Other East Indian 

 genera, sometimes represented in cultivation, are Vifex and Clerodendron. 

 Family Labiatae. Mint Family. This very large and important 



*The flat, expanded part of a corolla like that in a phlox flower, is known as the 

 limb in contra distinction to the inbe below. 



