Thilachium

Fici, Silvio, 2023, A new species of Thilachium (Capparaceae) from the Analanjirofo Region, Madagascar, Bothalia (a 4) 53 (1), pp. 1-6 : 4

Key to the species of Thilachium in Madagascar

1a. Leaves always simple or 1-foliolate: 2a. Inflorescence dense subumbel or corymb up to 16-flowered; pedicels 8–12 mm long............................................................................ T. latifolium Fici , sp. nov. 2b. Inflorescence loose corymbose raceme up to 10-flowered, or 2 or 3 flowers at the top of lateral twigs or on the branches; pedicels ≥ 12 mm long: 3a. Petioles ≥ 80 mm long; leaf blade ≤ 10 mm wide..................... T. pouponii Aubrév. & Pellegr. 3b. Petioles ≤ 40 mm long; leaf blade ≥ 18 mm wide: 4a. Petioles 8–12 mm long; inflorescence 8–10-flowered; stamens 25–30; anthers 2.5 mm long................................................................ T. monophylum Hadj-Moust. 4b. Petioles (11–) 19–40 mm long; inflorescence 2–6-flowered; stamens ≥ 30; anthers 1.5–2.0 mm long: 5a. Leaf blade subemarginate, 25–75 mm long; 4–6 flowers in terminal corymbs; pedicels (30–) 35– 50 mm long....................................................... T. laurifolium Baker 5b. Leaf blade acuminate (75–) 100–153 mm long; 2 or 3 flowers at the top of lateral twigs; pedicels 12–18 mm long................................................. T. madagascariense Fici

1b. Leaves 3-foliolate, rarely with simple leaves intermixed or on fertile branches: 6a. Leaflets linear or narrowly oblong, 2–12 mm wide; fruit 8–10 mm wide............. T. angustifolium Bojer 6b. Leaflets elliptic, lanceolate, oblanceolate, ovate, obovate or panduriform, (6–) 10–53 mm wide; fruit 12–40 mm wide: 7a. Leaflets heteromorphic, lanceolate and panduriform........................... T. panduriforme Juss. 7b. Leaflets not heteromorphic: 8a. Pedicels 6–8 mm long................................................... T. sumangui Bojer 8b. Pedicels 10–21 mm long: 9a. Gynophore 23–32 mm long; filaments 27–36 mm long........................ T. africanum Lour. 9b. Gynophore 7–20 mm long; filaments ± 10 m long: 10a. Pedicels ± 10–13 mm long; stamens ± 15; fruit 40–50 mm long.......... T. humbertii Hadj-Moust. 10b. Pedicels 15–20 mm long; stamens 30–40; fruit 7–8 mm long............... T. seyrigii Hadj-Moust.