4. Asystasia nemorum Nees in Wallich, Pl. Asiat. Rar. 3: 90. 1832.
十万错 shi wan cuo
Herbs to 1 m tall, perennial. Stems pilose. Leaf blade narrowly ovate to ovate-lanceolate, 6-12 × 3-5 cm, abaxially pilose along veins, adaxially glabrous or pilose along veins, secondary veins 6-9 on each side of midvein, base attenuate, margin undulate-crenulate, apex acuminate. Racemes terminal or axillary, 5-9 cm; bracts triangular, 2-3 × ca. 1 mm, pilose with gland-tipped trichomes; bracteoles similar to bracts. Pedicel 1-2 mm. Calyx 5-6 mm, outside pilose with gland-tipped trichomes; lobes lanceolate. Corolla red to purplish red, ca. 2.2 cm, outside pilose with gland-tipped trichomes, inside barbate in throat; lobes ovate, 4-5 × ca. 3.5 mm, unequal. Ovary and style pilose; stigma slightly 2-cleft. Capsule 1.8-2.2 cm. Seeds irregularly obovate in outline, 2-4 × ca. 2.5 mm, tuberculate-rugose. Fl. Aug-Oct, fr. Nov-Feb.
Paddy fields, streamsides, thickets. Guangdong, Guangxi, Yunnan [India, Laos, Myanmar, Thailand, Vietnam].
The plants misidentified as Asystasia chelonoides Nees by C. C. Hu (FRPS 70: 215. 2002) belong here.
Asystasia salicifolia can be difficult to distinguish from A. nemorum, and Chinese plants treated as these taxa might be conspecific. Indeed, according to R. Kiew and K. Vollesen (Kew Bull. 52: 965-971. 1997), A. nemorum has a compact inflorescence with flowers clustered toward the apex, a long and slender corolla tube, blue corollas, and is known only from Peninsular Malaysia (where cultivated) and Java (where native). It is possible that the plants treated here as A. nemorum are either not that species or represent cultivated plants of that species (which is used medicinally). Asystasia remains much in need of revisionary studies.