Croton

Kainulainen, Kent, Berry, Paul E. & Ee, Benjamin van, 2017, Rediscovery of two species of Croton (Euphorbiaceae) from littoral habitats of eastern Madagascar, Candollea 72 (1), pp. 35-44 : 36-37

Key to the species of Croton found in littoral forests on sandy substrates in eastern and southeastern Madagascar

1. Abaxial surface of leaves densely covered with lepidote trichomes ....................................................................... 2

1a. Abaxial surface of leaves glabrous or sparsely covered with stellate, lepidote, or stellate-lepidote trichomes.............. 3

2. Young stems lepidote; petiolar glands sessile; inflorescences elongate........................................... C. trichotomus

2a. Young stems velvety; petiolar glands stipitate; inflorescences congested ............................................ C. noronhae

3. Inflorescences elongate, spike- or raceme-like; largest leaf blades 5-16 cm long ....................................................... 4

3a. Inflorescences glomerate; largest leaf blades less than 5 cm long ................................................................................ 5

4. Inflorescences 1-4(-7.5) cm long, divergent; petioles 4-40(-60) mm long; leaves drying ± glossy; ovary and fruit stellate-pubescent.......................................... C. chapelieri

4a. Inflorescences 5-15 cm long, erect; petioles 2-15 mm long; leaves drying matte; ovary and fruit glabrous ................... ............................................................ C. vatomandrensis

5. Leaf blades sparsely lepidote, margins entire; petioles less than 5 mm long............................................... C. anisatus

5a. Leaf blades sparsely stellate, margins toothed; petioles 5-10 mm long ............................................. C. cassinoides