No. 438] NORTHERN GAM OPE TALOUS FLOWERS. 377 



bicolored with the calyx and corolla strongly contrasted ; £ '. 

 trichotomum from Japan has a white corolla and a red calyx, 

 while C. thorn some from tropical Africa has a snow white calyx 

 and a bright crimson corolla. 



The Labiatae is a large family of about 3000 species of widely 

 distributed plants, which are especially abundant in the region of 

 the Mediterranean. The foliage usually contains an aromatic 

 volatile oil. The flowers are distinctly zygomorphous, and 

 highly specialized both in form and color. In thus family and 

 the Scrophulariaceae the gamopetalous plants come to a second- 

 ary culmination. But while these two families belong to the 

 same order they are in different subseries, and are more closely 

 united witb other families than with each other. The Labiatae 

 connect with the Verbenacea\ both having one-ovuled carpels ; 

 and the Scrophulariaceae are related to the Solanaceae, both hav- 

 ing carpels with numerous ovules. 



The 120 species of the Labiatae contain 24 white, 4 yellow, 

 12 red, 47 purple and 33 'blue flowers. According to the 

 length of the corolla tube and the consequent limitation of the 

 insect visitors, the flowers may be arranged in three groups. 

 In Mentha and Lycopus the tube is short, and the visitors are 

 chiefly" flies. In Thymus, Origanum and Betonica bees become 



numerous. Vhile Stachys, Ajuga, Teucrium, Salvia. Lamium, 

 Galeopsis are almost exclusively fertilized by bees. Individually 

 the flowers are often inconspicuous and significance is gained by 

 massing. In Mentha and Lycopus the stamens are reduced to 

 four or two, the nearly regular corolla is 4-lobed, and the small, 

 pale purple or white flowers, which are fertilized chiefly by flies, 

 are in dense axillary whorls. These genera have evidently 

 retrograded and departed from the typical labiate form. The 

 flowers of Lyqppus are the smallest of this family. The small 

 flowers of Thymus and Origanum are in terminal clusters, 

 2-lipped with a five-cleft corolla. In both genera there uccur 

 large hermaphrodite and small pistillate flowers. Hie color is 

 purple and the visitors are flies, bees and butterflies, but t ic 

 largest percentage is of flies. The flowers of K>cellia d'yenan- 

 themum), or basil, are more or less bilabiate. They are small, 



