Isodon, , Li, 1988

Chen, Ya-Ping, Xiang, Chun-Lei, Sunojkumar, Purayidathkandy & Peng, Hua, 2016, Isodon villosus (Nepetoideae, Lamiaceae), a new species from Guangxi, China, Phytotaxa 268 (4), pp. 271-278 : 276

Key to the taxa of Isodon from Guangxi, China

1. Plants red-brown glandular.................................................................................................................................................................2

- Plants not red-brown glandular..........................................................................................................................................................5

2. Lamina narrowly lanceolate or elliptic-lanceolate ............................................................................................................... I. walkeri

- Lamina different from above..............................................................................................................................................................3

3. Corolla tube declinate, stamens and style included.............................................................................................................. I. villosus

- Corolla tube straight, stamens and style long exerted........................................................................................................................4

4. Lamina acute or obtuse at apex, broadly cuneate to rounded at base, light green or purplish beneath when dry ............................... ..................................................................................................................................................... I. lophanthoides var. lophanthoides

- Lamina acuminate at apex, cuneate at base, green to yellowish-brown beneath when dry ........... I. lophanthoides var. graciliflorus

5. Leaves in whorls of 3–4; upper part of mericarp trigonous ............................................................................................. I. ternifolius

- Leaves opposite; upper part of mericarp not trigonous......................................................................................................................6

6. Mericarp glandular, or glandular and pubescent................................................................................................................................7

- Mericarp glabrous.............................................................................................................................................................................11

7. Leaves lanceolate or narrowly lanceolate........................................................................................................................... I. nervosus

- Leaves different from above...............................................................................................................................................................8

8. Fruiting calyx erect, actinomorphic....................................................................................................................................................9

- Fruiting calyx decurved, obviously 2-lipped....................................................................................................................................10

9. Lamina serrate, calyx densely pubescent, mericarp glandular and pubescent ......................................................................... I. serra

- Lamina crenate, calyx glabrescent to sparsely hirtellous, mericarp glandular........................................................... I. amethystoides

10. Peduncle 2–4 mm long, calyx 2.7 × 3 mm, corolla ca. 8 mm long................................................................................ I. macrocalyx

- Peduncle ca. 8 mm long, calyx 4 × 6 mm, corolla up to 2 cm long ................................................................................ I. longitubus

11. Flowering calyx densely whitish floccose-tomentose, inflorescence narrow and spike-like............................................ I. eriocalyx

- Flowering calyx glabrescent or pubescent, inflorescence narrow or spreading but not spike-like..................................................12

12. Lamina cordate at base, occasionally subtruncate; flower yellow .............................................................................. I. sculponeatus

- Lamina never cordate at base; flower never yellow.........................................................................................................................13

13. Leaves lanceolate or narrowly lanceolate................................................................................................................. I. lungshengensis

- Leaves different from above.............................................................................................................................................................14

14. Perennial herbs, branchlets green, lamina 3.5–12 × 0.8–6 cm, panicles terminal and axillary.............................................. I. coetsa

- Shrubs, branchlets reddish, lamina 2–6 × 1.3–3 cm, panicles terminal ........................................................................... I. rubescens