Tridentea

Tridentea is a genus of succulent plant in the family Apocynaceae, endemic to southern Africa.^[1][2][3]

Tridentea
Tridentea gemmiflora
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Gentianales
Family:	Apocynaceae
Subfamily:	Asclepiadoideae
Tribe:	Ceropegieae
Genus:	Tridentea Haw.

Name and history

Stem specimen showing leaf remnants and flower stem

Tridentea was first described as a genus in 1812, and its name refers to the three "teeth" on each interstaminal segment of its flower ("tri-" = three; "dentis" = teeth). It was subsequently split, and the genus Tromotriche was created for the ten species which were separated.

Description

Vegetative features

Tridentea stems are typically smooth, soft and appear as roughly four-edged in cross section. The four angles are marked by rows of low tubercle mounds. In young growth, each tubercle bears a small splayed leaf-remnant. These fall off with time though. Each leaf remnant is always surrounded by several minute, fat hairs.

Floral features

Tridentea flowers are flattened, star-shaped, and usually brightly coloured. The most common colouring is a mixed mottling of greenish-yellow with purple. Their inside is usually densely papillate. Flowers appear on minute inflorescences, and each stem bears only one inflorescence, from the stem base.

Species^[4]

1. Tridentea aperta (Masson) L.C. Leach - southern Africa
2. Tridentea choanantha (Lavranos & Harry Hall) L.C. Leach - southern Africa
3. Tridentea dwequensis (C.A. Lückh.) L.C. Leach - southern Africa
4. Tridentea gemmiflora (Masson) Haw. - southern Africa
5. Tridentea herrei (Nel) L.C. Leach - southern Africa
6. Tridentea jucunda (N.E. Br.) L.C. Leach - southern Africa
7. Tridentea longii (C.A. Lückh.) L.C. Leach - southern Africa
8. Tridentea longipes (C.A. Lückh.) L.C. Leach - southern Africa
9. Tridentea marientalensis (Nel) L.C. Leach - southern Africa
10. Tridentea pachyrrhiza (Dinter) L.C.Leach - southern Africa
11. Tridentea parvipuncta (N.E. Br.) L.C. Leach - southern Africa
12. Tridentea peculiaris (C.A. Lückh.) L.C. Leach - southern Africa
13. Tridentea pedunculata (Masson) L.C. Leach - southern Africa
14. Tridentea ruschiana (Dinter) L.C. Leach - southern Africa
15. Tridentea umdausensis (Nel) L.C. Leach - southern Africa
16. Tridentea virescens (N.E. Br.) L.C. Leach

formerly included

Tridentea baylissii, syn of Tromotriche baylissii