Torenia (Hepper, 1987)

Fischer, Eberhard & Lachenaud, Olivier, 2013, A new species of Torenia (Linderniaceae) from Gabon, remarks on Torenia mannii Skan, and a key to the African and Madagascan Torenia species, Phytotaxa 125 (1), pp. 40-46 : 41

Key to the African and Madagascan species of Torenia

1. Anthers with distinct spur-like projections of the connective up 0.25 mm long. Endemic of Madagascar................... ................................................................................................................................................................ T. stolonifera

- Anthers without spur-like projections........................................................................................................................... 2

2. Corolla small, tube <7.5 mm long; calyx ridged to narrowly winged (wings <0.5 mm broad); widespread species of usually open habitats (swamps, ruderal vegetation, secondary forests, sometimes on rocks)...................................... 3

- Corolla larger, tube 8–15 mm long; calyx narrowly to broadly winged; uncommon species of forest habitats ......... 4

3. Leaves ovate to lanceolate; appendages of abaxial stamens short and indistinct, only a small knee-like bulge present, sparsely covered with glandular hairs; usually in open and secondary vegetation .................................... T. thouarsii

- Leaves orbicular; appendages of abaxial stamens distinct and spur-like, densely covered with glandular hairs and papillae; secondary forests and on rocks ..................................................................................................... T. dinklagei

4. Calyx lobes obtuse; corolla white with greenish-white to pink lower lip; abaxial stamens with geniculate filaments forming the letter Z ..................................................................................................................................... T. silvicola

- Calyx lobes acute; corolla pink or mauve with white markings; abaxial stamens with curved filaments bearing clavate appendages at base............................................................................................................................................ 5

5. Leaves much longer than broad, 30–45 x 14–25 mm (length:width ratio 2.1:1 – 1.8:1); calyx narrowly winged (wings <0.7 mm broad); corolla tube 11–15 mm long.................................................................................. T. mannii

5* Leaves not or hardly longer than broad, 20–28 × 20–25 mm (length:width ratio 1:1 – 1.12:1); calyx broadly winged (wings 1.5–2.5 mm broad); corolla tube 8–9 mm long................................................................................... T. daubyi