774 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. 



secretes honey. The Tubiflorse are distributed in every quarter of the globe. Several 

 families, such as the Loganiace« and Bignoniacese, are confined to tropical and sub- 

 tropical regions. The Acanthaceae also chiefly inhabit the warmer parts of the 

 earth. The genus Acanthus grows particularly in the region of the Mediterranean 

 Flora. The leaves of several species of Acanthus, e.g. Acanthus spinosissimus (see 

 vol. i. fig. 116, p. 437) and Acanthus mollis (see fig, 434), frequently served the 

 Greek and Roman sculptors as patterns for their ornaments. The genus Stapelia, 

 of the family Asclepiadaceae, is confined to the Cape; the Labiatse are most abundantly 

 represented in the Mediterranean Flora; the Gentianaceae and Scrophulariaceae 

 inhabit mountainous regions of the Old and the New World in large numbers of 

 different forms, and several species of the genera Gentiana, Veronica, Euphrasia, 

 and Pedicularis thrive best in proximity to glaciers both in mountain districts and 

 in the arctic regions. Fossil remains occur in the strata of the Tertiary period. 

 The number of species now living which have been identified up to the present 

 time is about 16,500. 



Oass III.— POLYPETAL^. 



Alliance LIII. — Ranales. 



Families: RanuncvXacece, Dilleniacece, Calycanthacece, Magnoliaceoe, Anonacece, 

 MenispermaceoB, Berheridacece, Lardizabalacece, Nymphceaceoe. 



Stamens rarely definite. Carpels, free or immersed in the receptacle, very rarely 

 connate. Embryo minute, embedded in a fleshy endosperm. In the Ranunculacese 

 the petals are not infrequently modified into honey-glands, and the sepals petalline. 

 The carpels are free from one another, and sometimes indefinite and spirally ar- 

 ranged, sometimes definite and whorled. In Calycanthus, the parts of the flowers 

 are inserted in a continuous spiral upon a hollow receptacle, and pass gradually the 

 one into the other. In Berberidaceae, the anthers open by means of valves. The 

 Nymphseaceae include marsh and water plants (e.g. Nymphcea, Nuphar, Nelumhium, 

 cf. fig, 436, Victoria Regia, Plate XL). In several of these the carpels are united 

 together into a large ovary with shield-like stigmatic disc. In Nelumhium (cf. 

 fig, 334, p. 440), the carpels are borne in distinct sockets. The fruit in the alliance 

 is very varied, and includes achenes, follicles, berries. Fossil remains occur in the 

 Tertiary Strata, Total number of living species about 3000 



Alliance LIV. — Parietales. 



Families: Sarraceniacece, Papaveracece, Fumariacecc, Cruciferoe, Capparidacece, 

 Moringacece, Resedacece, Cistinece, Violacece, Bixacece. 



Annual and perennial herbs, shrubs, and trees. Flowers solitary or in spikes, 

 umbels, racemes, and racemose cymes; actinomorphic and zygomorphic, herma- 

 phrodite and pseudo-hermaphrodite. Floral-leaves differentiated into calyx and 

 corolla; the calyx composed of a 2-5-partite whorl, the corolla of two 2-partite 



