PERSONATJ3. 529 



branches with haustoria, but growing with the base of its stem in close contact 

 with its host, and probably even often protruding a kind of thallus into it, in a 

 manner similar to the Loranthaceae. Its aerial shoots are not entirely destitute 

 of chlorophyll, but are not green ; they only bear scale-leaves and terminate in 

 a raceme or spike-like inflorescence. Some Oro&anc/te-species are detrimental 

 to various cultivated plants (Hemp, Lucerne, Tobacco, etc.). The flowers are 

 strongly zygomorphic ; the posterior sepal is often wanting, and the anterior are 

 united to the two lateral ones. Ovary unilocular, as in Gesneraceae, with 2 or 

 4 parietal placentae. The exceedingly small seeds have a very rudimentary 

 embryo, formed of an ellipsoidal, cellular mass, without indication of cotyledons 

 or other organs. About 100 species ; especially in the Mediterranean region. 



Order 6. Bignoniaceae. 500 species; nearly all trees and shrubs, and to a 

 great extent lianes, climbing by tendrils (modified leaves), which are sometimes 

 terminated by a special clasping apparatus. These lianes have, as a rule, an 

 anomalous stem structure, the wood being either divided into four wedges at right 

 angles to each other, separated by four grooves filled with secondary wood- 

 parenchyma, or a greater number of wedges occur, by the cambium ceasing to 

 form wood in several places. The leaves are most frequently opposite and com- 

 pound ; the flowers in the main are similar to the didynamous Scrophulariacese, 

 and especially resemble those of Digitalis purpurea ; they are bilabiate, large, 

 and beautiful, campanulate or trumpet-shaped, many of the prettiest ornamental 

 plants in the Tropics belonging to this order. The fruit is most frequently a 

 large, woody, 2-valved, siliqua-like, septifragal capsule, whose valves separate 

 from the flat and broad partition-wall, which bears the large, generally winged 

 :seeds : Tecoma ; Bignonia. In gardens : Catalpa syringcefolia (Trumpet-wood) ; 

 Tecomd radicana (from S. Am.). " Palisander "-wood is from Jacaranda (S 

 Am.). Eccremocarpus (N. Am.) forms, by its unilocular capsule, a transition 

 to the Gesneriaceae (E. scaber; herbaceous). 



Crescentia is allied to this order ; C. cujete (Calabash) is its best known 

 .species. The fruit (unilocular with 2 parietal placentae) is a very large, 

 spherical or ellipsoidal berry, with a firm, finally woody outer layer. After 

 the removal of the juicy interior, these are commonly used as drinking vessels 

 in Tropical America. 



Order 7. Pedaliaceae. Sesamum (orientale and indicum) ; very important 

 oil-plants, which from olden times have been cultivated in tropical Asia and 

 Africa for food and as medicinal plants, and are now cultivated in America 

 also. The seeds are used as a raw material in the manufacture of soap in 



Europe. To this order also belong Martynia and Craniolaria, which have a 



long horned capsule and sensitive stigmas. 46 species. 



Order 8. Acanthaceae. 1,500 species; mostly erect, slender, branched 

 herbs or shrubs, rarely arborescent, especially in S. Am. and Ind. The 

 .branches frequently have swollen nodes ; the leaves are opposite, penninerved, 

 undivided, more or less lanceolate or elliptical, and generally leave a distinct 

 scar when they fall off. Stipules are wanting. The flowers are solitary or in 

 dichasia, which are arranged in 4-rowed spikes or racemes, each flower with 

 its subtending bract, which may be brightly coloured, and most frequently also 

 with two bracteoles. With regard to the corolla (which is often labiate, in any 

 .case irregular, and frequently prettily coloured), the 2 or 4 didynamous stamens 



