1A.	Stipules 5 mm diameter or wider at base, swollen, myrmecophiles (inhabited by ants) or flattened and sword- or boat-shaped	2
1B.	Stipules less than 5 mm in diameter, never swollen at the base	3
2A	Inflorescences arranged in cylindrical spikes; secondary venation of leaflets usually visible	V. cornigera
2B.	Inflorescences arranged in spheric capitula; secondary venation of leaflets usually not easily visible	V. sphaerocephala
3A.	Pinnae 12 or more pairs per leaf	V. pennatula
3B.	Pinnae 9 or fewer pairs per leaf	4
4A.	Inflorescences arranged in cylindrical spikes	5
4B.	Inflorescences arranged in spheric capitula	6
5A.	Leaflets 2–3 pairs per pinna, large, all or most of them 1 cm wide or wider	V. californica ssp. pringlei
5B.	Leaflets 3–5 pairs per pinna, smaller, the largest 8 mm wide or narrower	V. rigidula
6A.	Fruits indehiscent, septate internally; whorl of bracts at the apex of the peduncle immediately below the capitulum	7
6B.	Fruits dehiscent, non-internally septate; whorl of bracts near mid-peduncle	9
7A.	Petiolar gland elliptic; below, in the middle of, or at the apex of the petiole; fruit 3–6.5 cm long, inflated, black or dark brown, glabrous, without minute reddish glands	V. farnesiana ssp. farnesiana
7B.	Petiolar gland circular, located immediately below the first pair of pinnae; fruits 6.5–15 cm long, pubescent, rarely glabrous, with minute reddish deciduous glands	8
8A.	Secondary shoots (brachyblasts) thick, 3–4 mm diameter; pinnae 3–5 pairs per leaf; fruit compressed, 9 mm wide or wider, slightly constricted between the seeds	V. schaffneri
8B.	Secondary shoots (brachyblasts) thin, 2–3 mm diameter; pinnae 2–3 pairs per leaf; fruit subcylindrical, 8 mm wide or less, usually constricted between the seeds	V. bravoensis
9A.	Petiole wide canaliculate, 3.5 mm long or shorter; fruit non-striated, with numerous reddish, pedicellate, 1 × 0.2 mm glands	V. glandulifera
9B.	Petiole narrowly canaliculate, usually 4–11 mm long; fruits striated, glabrous or with tiny reddish-brown glands, not pedicelled, less 1 × 0.2 mm	10
10A.	Leaf rachis 15 mm long or longer; pinnae 3–6 (-7) pairs per leaf; leaflets not glutinous; fruits non-glutinous, with tiny reddish-brown glands	V. constricta
10B.	Leaf rachis 5 mm long or shorter; pinnae 1–2 (-3) pairs per leaf; leaflets glutinous; fruits glutinous, glabrous	V. vernicosa