Isodon walkeri (Arn.) H.Hara

Suddee, S., A. J. Paton, & Parnell, J. (2004). A Taxonomic Revision of Tribe Ocimeae Dumort. (Lamiaceae) in Continental South East Asia I. Introduction, Hyptidinae & Hanceolinae. Kew Bulletin, 59(3), 337-378. doi:10.2307/4110949

Distribution

India, Sri Lanka, South China, Burma, Laos & Vietnam.

Ecology

In sandy soil in river beds in mixed or evergreen forest, on rocks beside stream; 600 - 1200 m.

Morphology General Habit

Erect or ascending annual herb up to 80 cm tall

Morphology Leaves

Leaves chartaceous, narrowly lanceolate or elliptic-lanceolate, 15 - 110 x 7 - 25 mm, apex acute, base cuneate or attenuate and decurrent on petiole, margin serrate above the middle or for 2/s of leaves' length, entire below, scaberulous on midrib above and beneath, otherwise glabrous or glabrescent, dotted with minute sessile glands beneath or both sides, veins prominent beneath; petioles subsessile to 30 mm long, puberulous or pubescent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens long- exserted from anterior corolla lip, villous at base, posterior pair inserted near the base of corolla tube, anterior pair inserted around the middle or corolla tube

Morphology Reproductive morphology Flowers Calyx

Calyx tubular-campanulate, conspicuously 2-lipped, c. 2 mm long at anthesis, 3 - 5 mm long in fruit; posterior lip shortly 3-lobed, ovate, acute at apex, median lobe broadest; anterior lip 2-lobed, ovate-oblong, acute or obtuse at apex, subequal in length to posterior or longer; tube declinate, 10- nerved, twice as long as calyx teeth, puberulous on nerves, with sessile glands, not gibbous at anterior base

Morphology Reproductive morphology Flowers Corolla

Corolla white, straight, 6 - 7 mm long; posterior lip subequally and deeply 4-lobed, lobes obtuse or rounded at apex, slightly pubescent, with sessile glands on back; anterior lip orbicular, 2 - 3 mm long, equal or slightly longer than posterior, flattened, glabrous; tube straight, subtubular, 3- 4 mm long, only slightly gibbous above posterior base, slightly dilated at throat, pubescent on anterior side inside, glabrous or glabrescent outside

Morphology Reproductive morphology Flowers Disc

Disc obscurely lobed

Morphology Reproductive morphology Flowers Gynoecium Style

Style subequal to anterior stamens

Morphology Reproductive morphology Fruits

Nutlets brown, ovoid or oblong, 1 - 2 mm long, smooth or minutely tuberculate, not or slightly producing mucilage when wet.

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, forming a narrow panicle, 5 - 15 cm long; axis with indumentum similar to stem; verticils 5 - 40 mm apart; cymes lax, few- to many-flowered, lateral branches short, not conspicuously cincinnate, each 2 - 3-flowered; bracts elliptic or lanceolate; bracteoles oblong or linear, 0.5 - 2 mm long, obtuse, ciliate, pubescent, persistent or caducous; pedicels slender, 2 - 4 mm long at anthesis, 2 - 7 mm long in fruit, pubescent

Morphology Stem

Stems sometimes rooting at nodes below, sometimes branched, quadrangular, puberulous below, strigose or puberulous above

Phenology

Flowering & fruiting November - February.

Type

Sri Lanka, Hb. Hort. Soc. 1839, Mackenzie s.n. (K!, neotype chosen here).