Cardiopteridaceae

Nuraliev, Maxim S., Schori, Melanie, Tagane, Shuichiro, Kuznetsov, Andrey N., Kuznetsova, Svetlana P. & Utteridge, Timothy M. A., 2022, Citronella suaveolens, a new generic record for Vietnam, with a key to Vietnamese Cardiopteridaceae, Phytotaxa 532 (1), pp. 67-77 : 72

Key to the genera and species of Cardiopteridaceae in the flora of Vietnam

Distinction of genera is based on Schori (2016); key to the species of Cardiopteris follows Gagnepain (1911).

1. Liana with whitish latex; leaf blade entire or lobed, truncate to cordate at base, palmatinerved; corolla gamopetalous; stamens epipetalous; fruit a samara with a fleshy terminal appendage....................................................................................2 ( Cardiopteris )

- Trees or shrubs without latex; leaf blade entire, acute to obtuse at base (never cordate), penninerved; corolla choripetalous or gamopetalous; stamens free or epipetalous; fruit a drupe ..................................................................................................................3

2. Inflorescence with 2–6 cincinni; fruit stipe not or shortly exceeding calyx, ca. 2 mm long; fruit distinctly longer than wide, obcordate .................................................................................................................................................... Cardiopteris quinqueloba

- Inflorescence with 15 or more cincinni; fruit stipe greatly exceeding calyx, 7–8 mm long; fruit oval to nearly circular in outline... ....................................................................................................................................................................... Cardiopteris platycarpa

3. Flowers unisexual; corolla gamopetalous, tube often longer than lobes; stamens epipetalous, included in corolla............................ ............................................................................................................................................................... Gonocaryum ( G. lobbianum )

- Flowers bisexual or unisexual; corolla choripetalous; stamens free, exserted from corolla (in female flowers, staminodes included) .................................................................................................................................................... Citronella ( C. suaveolens )