Table 2.

Morphological comparison of Chayamaritia vietnamensis and its two relatives.

Characters	C. vietnamensis	C. banksiae	C. smitinandii
Leaf blade	peltate, 1.2–1.3 times as long as wide, apex rounded, margin entire	palaceous, 1.5–1.9 times as long as wide, apex shortly acuminate, margin minutely dentate	palaceous, 1.8–5.6 times as long as wide, apex acuminate, margin minutely dentate
Bracts	3, narrow ovate, 5–6 mm wide, apex rounded, margin entire	2, ovate, 19 mm wide, apex acuminate, margin dentate	2, narrowly elliptic to lanceolate, somewhat falcate, 1.8–8 mm wide, apex acuminate, margin entire
Pedicels	25–35 mm long	12–15 mm long	6.5–11 mm long
Calyx lobes	4–6 mm wide, inside glabrous, margin entire	7–15 mm wide, inside with white appressed hairs in the upper half, margin coarsely dentate	0.9–4.2 mm wide, inside densely pubescent, margin slightly toothed or appearing as large sessile glands on margin
Corolla	outside dark purple throughout, lobes margin entire	outside white ventrally, lobes being minutely dentate along the margin	outside deep purple throughout, lobes margin entire
Lateral staminodes	2.5–4 mm long	5.5–11 mm long	4–5 mm long
Disc	ca. 3 mm high	ca. 1.5 mm high	0.9–1.4 mm high