122 27- BROMEI.IACEAE -- 28. COMMELINACKAE 



FAMILY 27. BROMELIACEAE 



Herbs. Leaves for the most part radical, linear, toothed. Inflorescence 

 terminal, cone-shaped. Flowers regular, hermaphrodite. Perianth consisting 

 of a calyx and a corolla. Petals slightly cohering and bearing two scales at 

 the base. Stamens 6, slightly adhering to the petals. Anthers hnear, turned 

 inwards. Ovary inferior or half-inferior, 3-celled, wdth many axile, inverted 

 ovules. Style i ; stigmas 3. Fruits berry-like, united into a cone-shaped 

 head. Embryo near the base of the mealy albumen. 



Genus i, species i {A. sativus Schult., pine-apple). Cultivated and often 

 naturalised in the tropics. The edible fruit and the fibres of the 

 leaves are used. {Ananassa 'LmdX.) Ananas Adans. 



SUBORDER COMMELININEAE 



FAMILY 28. COMMELINACEAE 



Herbs. Leaves alternate. Inflorescence cymose. Flowers hermaphrodite. 

 Perianth-segments 6, more or less distinctly separated into sepals and petals. 

 Fertile stamens 2 — 6. Ovary superior, 2 — 3-celled. Ovules straight. Style 

 terminal. Embrj^o near the apex of the more or less mealy albumen. — Genera 

 12, species 160. (Plate 16.) 



1. Fruit indehiscent, ovate or globular. Ovary 3-celled. Petals free, white, 



more rarely pale pink or blueish. Inflorescence a panicle without 



spathe-like bracts. [Tribe POLLIEAE.] 2 



Fruit dehiscing loculicidally 3 



2. Pericarp succulent. Margin of the leaves silky. Perfect stamens 3. — 



Species 10. West Africa and Upper Nile. Some are used as ornamental 



plants. Palisota Reichb. 



Pericarp crusty. Margin of the leaves nearly glabrous. Perfect stamens 

 3 or 6. — Species 5. Tropics Pollia Thunb. 



3. Fertile stamens 2 — 3, sterile ones — 4, often bearing empty anthers. 



[Tribe COMMELINEAE.] 4 



Fertile stamens 5—6. [Tribe TRADESCANTIEAE.] .... 7 



4. Inflorescence in the axil of spathe-like bracts 5 



Inflorescence without spathe-like bracts 6 



5. Sterile stamens with linear anther-halves cohering at the base. Ovary 



2-celled with i ovule in each cell. Petals white. Spathes on the 

 elongate branches of a panicle. — Species i. West Africa. 



Polyspatha Benth. 



Sterile stamens with cross-shaped anthers. Ovary usually 3-celled. Petals 



usually blue. — Species 80. Some have an edible root-stock or yield 



vegetables, medicaments, or dyeing-materials ; others are used as 



ornamental plants . Commelina L, 



6. Sepals large, equal, lanceolate, acute. Petals equal. Fruit with 3 equal- 



sized, many-seeded cells. — Species i. East Africa. Anthericopsis Engl. 



