654 



BOTANY 



PART II 



bluish violet. Cerinthe is completely glabrous, and has a waxy covering to the 



epidermis. Ueliotropium, a favourite ornamental 

 plant, has an undivided ovary. 



Family 5. Verbenaceae. — Shrubs or trees, rarely 

 herbs, with zygomorphic flowers. K 5, C (5), A 4, 

 G(2). Distinguished from the following family 

 by the terminal position of the style (Fig. 692 A), 

 Almost all tropical or sub-tropical. Only Verbena 

 officinalis occurs in Britain. Lantana is a widely 

 spread weed in the tropics. Tcctona grandis C^^), a 

 deciduous tree of the dry regions of the East Indies, 

 yields the important timber teak. Aviccnnia (''"), 

 trees of the mangrove vegetation, with viviparous 

 Iruits and pneumatophores (Fig. 193). Clero- 

 dendron includes some myrmecophilous species. 



Family 6. Labiatae. — Distributed over 

 the earth. Herb.s or .shrubs with quadrang- 

 uhir stems aud decussate leaves without 

 stipules. Leaves simple ; plants often 

 aromatic owing to the presence of glandular 

 hairs. Flowers solitary in the axils of the 

 leaves, or forming apparent whorls. The 

 small inflorescences are dichasia or double 

 cincinni, and are often united in larger 

 spike- or capitulum - like inflorescences. 

 Flower zygomorphic (Fig. 693). Calyx 

 gamosepalous, w^ith five teeth ; corolla two- 

 lipped, the upper lip consisting of two, the 

 lower of three petals ; stamens in two pairs, 

 two long and two short, rarely only two. 



Ovary of two car- 

 pels, each of which 

 is deeply indented 

 in the plane of 

 the false septum. 

 Style springing 

 from between the 

 lobes; stigma bifid 

 (Fig. 692 B). A 

 ring-shaped nec- 

 tary situated at the 

 base of the ovary. 

 Fruit, a schizocarp, 

 consisting of four 



Fio. 



ERA. 



&'3b.— Salvia officinalis. Flowering shoot (i nat. size). Tubular nutlets. 

 corolla slit open to di.splay the stamens (enlarged). 



Important Gen- 



— The Labiatae include a considerable proportion of our commonest native 



