Table 2. Comparison of Sonerila souvannii Phonep. & Soulad. sp. nov., S. cardamomensis S.H.Cho, S. dongnathamensis Suddee, Phutthai & Rueangr., and S. tuberosa C.Hansen. 1 = from Sinh et al. 2020; 2 = from Suddee et al. 2014; 3 = from Hansen 1989.
Characters S. souvannii S. cardamomensis 1 S. dongnathamensis 2 S. tuberosa 3
Rhizome cylindrical, 0.8–1 cm in diam. bulbous, 0.4–1 cm in diam. globose (size unknown) a slightly bulb-shaped tuber, 2–4 mm long and wide, completely covered with a dense 0.5 mm thick layer of pale brown intertwined curly hairs
Stem ca 2 cm long, green 4-sided, tinged purplish, internodes almost absent absent acaulescent herb ca 6 cm high
Lamina (ordinary leaves) ovate, 8–10 × 6–9 cm ovate, 1–4 × 0.9–2.7 cm ovate to rounded, 2–7 × 2.5–6 cm very broadly ovate to orbicular, ca (0.5–)1.6–2 cm long and wide; base very broadly cordate, apex very broadly rounded, margin entire to subdenticulate
Number of lateral primary veins 4–5 pairs 2–3 pairs 2–4 pairs 7-nerved, all nerves indistinct and only middle one reaching apex
Petioles 8–15 cm long, light green, densely villous 0.4–2.5 cm long, reddish, covered with glandular trichomes 5–15 cm long, white to pinkish green, densely villous 3–4 cm long
Pedicel 10–25 mm long, sparsely covered with glandular trichomes 4–5 mm long, covered with glandular trichome 1–4 mm long, glabrous 5–6 mm long
Inflorescence scorpioid cyme scorpioid cymes scorpioid cymes scorpioid cymes
Number of flowers per inflorescence 20(–25) flowers 5–11 flowers 5–12 flowers 4–8 flowers
Hypanthium size 5–6 × 2–2.5 mm 3.5 × 1.3–1.5 mm 1.5–4 × 1.5–2 mm ca 3.5 x 1 mm
Petal 9–10 × 6–7 mm, glabrous 5.5–6 × 3.5–4 mm, abaxially glandular trichomes on midvein 3–5 × 3–4 mm, glabrous 5 × 2.7 mm, elliptic, apiculate, thin, pink
Capsule 5–7 × 2.5 mm, glabrous 3.5–4.0 × 2–2.2 mm, glabrous 5–7 × 2–2.5 mm long, glabrous ca 4.5 x 1.5 mm, glabrous