Cascabela, Rafinesque, 1838

Alvarado-Cárdenas, Leonardo O. & Núñez, José Carmen Soto, 2014, A new species of Cascabela (Apocynaceae; Rauvolfioideae, Plumerieae) from Michoacán, Mexico, Phytotaxa 177 (3), pp. 163-170 : 169

Key of the species of Cascabela

1 Leaves with inconspicuous secondary venation.................................................................................................................................2

- Leaves with conspicuous secondary venation....................................................................................................................................4

2 Leaves obovate to oblanceolate, membranaceous to subleathery, glabrous; flowers greenish-yellow................ Cascabela gaumeri

- Leaves filiform, linear to lanceolate, membranaceous, glabrous or sparsely puberulent; flowers yellow or orange ........................3

3 Leaves sessile, linear to filiform, sparsely puberulent on both surfaces; inflorescence peduncles 8–30 mm ...... Cascabela pinifolia

- Leaves petiolate, lanceolate to elliptic-lanceolate, glabrous on both surfaces; inflorescence peduncles 3–9 mm .............................. ............................................................................................................................................................................... Cascabela thevetia

4 Leaves obovate to oblanceolate, leathery.................................................................................................................. Cascabela ovata

- Leaves linear-lanceolate to elliptic-lanceolate, membranaceous to subcoriaceous............................................................................5

5 Leaves pubescent on both surfaces, lower corolla tube 8–12 mm .................................................................... Cascabela balsaensis

- Leaves glabrous adaxially, sparsely tomentulose abaxially, lower corolla tube 20–30 mm. .......................... Cascabela thevetioides