28. COMMELINACEAE — 29. PONTEDERIACEAE 123 



Sepals small, unequal, ovate or oblong-ovate, obtuse. Petals unequal. 

 Fruit with 2 cells, more rarely with 3, one of which is smaller and 1—2- 

 seeded. — Species 30. Tropical and South Africa. Some are used as 

 ornamental plants. (Plate 16.) .... i' . Aneilema R. Br. 



7. Petals united below into a tube, but sometimes free ä't the base, blueish or 



reddish. Ovary 3-celled with i — 2 ovules in each cell. ... 8 

 Petals' free or nearly so 9 



8. Stamens inserted towards the top of the corolla-tube. Petals united from 



the base, — Species 5. Tropical and South Africa. Coleotrype C. B. Clarke 



Stamens inserted at the base of the corolla. . Petjals free at the base. — 



Species 15. Tropical and South Africa. Some are used as ornamental 



plants. Cyanotis Don 



9. Ovary 2-Gelled with i ovule in each cell. Fruit ovate. Filaments glabrous. 



Petals fed or yellow. Inflorescence a panicle. — Species 9. Tropical 

 and South-east Africa. Some are used as ornamental plants. 



Floscopa Lour. 

 Ovary 3-celled 10 



10. Ovules 4 — 10 in each cell. Fruit oblong. Filaments glabrous. Petals 



whitish. Inflorescence a panicle. — Species 2. Central Africa!. ' 



Buforrestia C.- B. Clarke 

 Ovules I — 2 in each cell. Fruit ovoid or globular. Stamens hairy. In- 

 florescence spike-, head-, or umbel-like . . . II 



11. Ovules 2 in each cell ; in the dorsal cell sometimes solitary. Fruit sub- 



globular. Stamens with a narrow connective. Sepals herbaceous, green. 

 Inflorescence spike- or head-like. Stem long. — Species 3. Equa- 

 torial West Africa Forrestia A. Rich. 



Ovule I in each cell. Fruit ovoid. Stamens with a broad connective. 

 Sepals subpetaloid. Inflorescence umbel-like, and surrounded by an 

 involucre of two bracts. Stem short.- — Species i. West Africa (Congo). 



Rhoeo Hance 



SUBORDER PONTEDERIINEAE 



FAMILY 29. PONTEDERIACEAE 



Aquatic herbs. Flowers in spikes racemes or panicles, without bracts, 

 hermaphrodite. Perianth-segments 6, petaloid, white yellow or blue, united 

 below into a tube, rarely nearly free. Stamens 3 or 6, affixed to the perianth. 

 Anthers oblong. Ovary superior, i- or 3-celled, with numerous inverted 

 ovules. Style simple. Fruit a loculicidal, many-seeded capsule. Seeds with 

 a ribbed testa, a copious mealy albumen, and a long cylindrical embryo. — 

 Genera 3, species 5. Tropics. 

 I. Stamens 3. Ovary i-celled or incompletely 3-celled. Perianth funnel- 

 shaped, with a distinct tube. — Species 3. Central Africa. 



Heteranthera Ruiz & Pav. 

 Stamens 6. Ovary 3-celled. Perianth blue or violet 2 



