252 THE THUNBERGIA AND THE FOXGLOVE FAMILIES. 



Phlomif, Staclqii!. Dracocephalum, Betonica. and Melissa; the Lavandula pin- 

 nata, and tlie Colcus Bluvieii, the latter an ocenpant of the green-house, and 

 distinguished by its ovate, serrate, and pointed leaves having the centre occupied 

 by a deep reddish-bro^^•n stain. The flowers are blue, and bonie in a long upright 

 raceme. 



LXXIII.— THE THUNBERGIA FAMILY. Acaiithdcew. 



The Acanthaceee, like many other families, are almost exclusively 

 tropical in their native stations, where they constitute a large part of 

 the weedy herbage. In a very few instances do they advance north- 

 wards, the celebrated Acanthus of Greece, the plant which gave to 

 Callimachus the idea of the Corinthian capital, being the only case in 

 which the family is represented in Europe. They are of very slender 

 importance economically, but often in their blossoms of the most rare 

 and delicious beauty. Every grower of hot-house flowers knows that 

 elegant climber, the ThunMrgia, with large, flat, bufi*- coloured or 

 white corollas, and a dark spot in the centre ; also the splendid 

 Justicias and Apheldndras, the charming Ruellias, and the Ci-ossundra. 

 In the majority of cases these handsome plants may be recognized by 

 the abundance of their large and leafy bracts, two or three of which 

 accompany every flower, and by the calyx being composed of four or 

 five deeply imbricated sepals. The corolla, as in the other families of 

 this alliance, is formed of four or five united petals, and rather 

 irregular ; the stamens, which are inserted on the corolla, are usually 

 two, but sometimes four, and then didynamous ; the ovary is solitary, 

 free, and two-celled. The calyx, in the genus Tlnmhh-gia, is reduced 

 to a mere ring, and its place sup])lied by the characteristic bracts. 

 The leaves are opposite, simple, undivided, and entire, or occasionally, 

 as in the case of the classical Acanthus, beautifully lobed and waved. 



LXXIV.— THE FOXGLOVE FAMILY. Scrofulariacca. 



The plants of which the foxglove is the type constitute one of the 

 largest and most widely difiused families of Botany. The species 

 amount to nearly 2,000, and are found everywhere, from Melville 

 Island to Tierra del Fuego ; no country is too hot, or too cold, or too 

 ungenial for them. They are mostly herbaceous, though in a few 

 cases undcrshrubby ; usually scentless, but occasionally, as in the 



