Coleus bracteatus Dunn

Suddee, S., A. J. Paton, & Parnell, J. (2004). A Taxonomic Revision of Tribe Ocimeae Dumort. (Lamiaceae) in Continental South East Asia II. Plectranthinae. Kew Bulletin, 59(3), 379-414. doi:10.2307/4110950

Type

China, Yunnan, Puerh, 1350 m, Henry 13498 (K!, lectotype chosen here; isolectotype NY).

Morphology General Habit

Erect or ascending annual herbs up to 1.5 m tall

Morphology Stem

Stems succulent, branched, round-quadrangular, puberulous

Morphology Leaves

Leaves membranous, ovate, 30 - 120 x 20 - 70 mm, apex acute, base cordate or subtruncate, margin crenate, puberulous above, puberulous on nerves otherwise glabrous with or without sessile glands beneath; petioles slender, 10 - 50 mm long, puberulous

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, simple, up to 25 cm long; verticils 10 - 50 mm apart, clearly interrupted; cymes 1 - 3 cm long, pedunculate, producing lateral cincinni, few to many-flowered; bracts membranous, sessile, early-caducous, broadly ovate-orbicular, up to 10 x 10 mm, acute, shortly ciliate at margin, pubescent; pedicels 1 - 2 mm long at anthesis, 3 - 4 mm long in fruit, shortly pubescent

Morphology Reproductive morphology Flowers Calyx

Calyx tubular-campanulate, 2 - 3 mm long at anthesis, 6- 7 mm long in fruit; posterior lip ovate, acute at apex, margin entire or shortly ciliate, decurrent on tube, glabrous with prominent veins inside, glabrescent with sessile glands outside; anterior lip with teeth subequal, lanceolate, subequal in length to posterior; tube 10-nerved, glabrescent or pubescent with sessile glands outside, slightly gibbous at anterior base

Morphology Reproductive morphology Flowers Corolla

Corolla bluish-purple, 10 - 20 mm long; posterior lip with lobes rounded at apex, pubescent with sessile glands on back, median lobes larger than lateral lobes; anterior lip ovate-oblong, 5-6 mm long, concave, pubescent with sessile glands outside, villous inside; tube 8 - 15 mm long, abruptly recurved beyond calyx, gradually dilated towards throat, pubescent with sessile glands outside

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens very short, attached below the base of anterior corolla lip and included in it, anterior pair slightly united at base

Morphology Reproductive morphology Flowers Gynoecium Style

Style shortly cleft and capitate at apex, subequal to posterior stamens

Morphology Reproductive morphology Flowers Disc

Disc with anterior side obtuse or truncate at apex, exceeding and up to twice as long as ovary

Morphology Reproductive morphology Fruits

Nutlets black or brown, ovoid, c. 1 mm long, smooth, shining, not producing mucilage when wet.

Distribution

South China, Vietnam & Thailand.

Ecology

Open areas in hill evergreen forest, on limestone rocks in evergreen forest; 700 - 2000 m.

Phenology

Flowering & fruiting August - December.

Note

This species is characterised by the very long corolla tube and the short stamens which are attached below the base of the anterior corolla lip. The species can also be easily distinguished from other Plectranthus species by the large ovate-orbicular bracts but these can rarely be seen on herbarium specimens as they are early-caducous. The capitate stigma is unique in the genus, and similar to that of Orthosiphon. There are 2 syntypes at K collected by Henry from Southern China. The more complete specimen, Henry 13498, is chosen as the lectotype.