Tên Khoa học: Camellia sonthaiensis Luu, Luong, Q.D. Nguyen & T.
Tên tiếng Anh:
Tên tiếng Việt: Trà sơn thái
Tên khác:

Shrub 2-5 in high, evergreen, with an arch­ing stem, sparsely branched, branches slen­der; new shoots purple, slimy, glabrous; young branches purple, glabrous, shiny, flexuous; mature branches light brown, with longitudi­nally fissured bark. Leaves pendulous, glabrous, narrowly lanceolate, obtuse at base, acumi­nate at apex, with shallowly toothed, undulate margin; young leaves purple, shiny; mature leaves coriaceous, shiny on both sides, adaxially light green, abaxially pale green, (10)17-30 cm long, (1.8)4—5.6 cm wide; midrib prominent on both sides; secondary venation brochidodro- mous, with 13-18 pairs of arched veins, adaxi­ally slightly raised, abaxially prominent; tertiary venation adaxially distinct, abaxially indistinct; leaf petioles purple and straight when young, light green and falcate when mature, partially obstructed by leaf lamina on adaxial side, adaxi­ally channelled, glabrous, 1-1.2 cm long, 2.5-3.0 mm wide, thick, angle of attachment variable: between 30° and 90°. Flowers pedunculate, 1-3, borne on a short bracteate shoot in axils of old leaves; short shoots ca. 2 mm long, bracts (sensu  Sealy 1958) 3-4, triangular or ovate, concave, compacted, subtending flower, 1.5 mm long x nun wide, glabrous; flower buds ovate, fer­ruginous; open flowers evenly circular, ca. 5 cm in diameter; pedicels stout, brownish green or brown, shiny or crackled and corky, 12-15 mm long, 2 mm wide at proximal end, 3 mm wide at distal end; bracteoles (sensu Sealy 1958) 2-3, triangular, appressed to and scattered along pedi­cel, hairy on outer surface, ca. 2 mm long, 1 mm wide, distinctly differentiated from sepals; sepals 5, persistent, ovate, concave, coriaceous, finely hairy on outer surface, with translucent margin, 6-12 mm long, 10-19 mm wide, centrally green, marginally light yellow, arranged in 2 whorls forming a rather loose spiral, outer whorl of 2 sepals and inner whorl of 3 sepals; petals 7, finely hairy on outer surface, with translucent margin, concave, 14-16 mm long, 16-18 111111 wide, arranged in 3 whorls; outer whorl distinct with 3 petals, petals centrally green, distally light yellow; middle and inner whorls of 2 petals each, petals yellow, with re volute margins; stamens numerous, arranged in 3 whorls; filaments ca. 260, lightly yellow, 13-18 mm long, basally united to each other for 3 mm, free above union, inner filaments basally sparsely hairy, outer fila­ments glabrous, basally united to petals for 3-5 nun, free above union; anthers yellow, 2 nun long, 1 nun wide, with two longitudinal stria­tions, dorsifixed; styles 4 (sometimes 3), free, basally densely hairy, 9-10 nun long, 1 nun wide at base, 0.5 mm at apex, yellowish green, stigma indistinct; ovary superior, ovoidal termi­nating into (3)4 styles, slight longitudinal stria­tions, yellow, finely white hairy, 4 (sometimes 3) carpellate, ca. 5 mm long, 3-4 mm in diameter, 2 ovules per locule. Mature fruits capsular, corky, 3-3.5 cm in diameter, 1.5-2 cm deep, with per­sistent sepals, dehiscing distally into 4 parts; columella stout, 0.8-1.1 cm long, 4-5 nun wide; seeds not seen.