Bituminaria, Heist. ex Fabricius, 1759

Minissale, Pietro, Brullo, Cristian, Brullo, Salvatore, Galdo, Gianpietro Giusso Del & Sciandrello, Saverio, 2013, Bituminaria basaltica (Fabaceae), a new species from Italy, Phytotaxa 98 (1), pp. 1-15 : 12

Key to the species of Bituminaria

1. Plants acaulescent; leaflets sessile, denticulate; racemes ovoid to ellipsoid .................................................. B. acaulis

- Plants caulescent; leaflets petiolate, entire; racemes capitate....................................................................................... 2

2. Cauline leaflets linear; corolla purely white; flowers 11–13 mm long ........................................................ B. basaltica

- Cauline leaflets wider (not linear); corolla pink to blue-violet or white-violet; flowers 15–20 mm long.................... 3

3. Racemes 5–8 flowered; calyx 9–11 mm long;, corolla pink; pods 10 mm long (including persistent beak)................. ....................................................................................................................................................................... B. flaccida

- Racemes 10–30 flowered; calyx 14–18 mm long; corolla white-violet to blue-violet; pods, pod 13–26 mm long (including persistent beak) ............................................................................................................................................ 4

4. Plants woody at the base;, leaflets glabrous or subglabrous adaxially; racemes 3–4.5 mm long.............. B. morisiana

- Plants entirely herbaceous; leaflets hirsute; racemes 2.0– 2.8 mm long ................................................... B. bituminosa