Scientific name: Camellia capitata Orel, Curry & Luu
English name:
Vietnamese name: Trà đầu
Other name:

Perennial, medium to large evergreen shrubs to 5 m high, with upright habit, sparsely branched, sometimes multi-stemmed; stems thin; secondary branches light and ascending at ca. 45° angle; mature bark generally smooth, with areas of shallow striations, without sheen, grayish to light brown, with mid- to dark brown, randomly distributed areas of pigmentation, with some lichen growth present; new shoots rather thin, initially light green, later gray to brown, glabrous, dull; mature branches concolorous to trunk. Petiole falcate, short, and stout, 1-1.5(—1.8) X 0.2-0.4 cm, mid- to dark green, finely hairy, the hairs white, with a variably deep but rather shallow longitudinal channel on its adaxial side; axillary leaf buds few, small, rudimen­tary, laterally compressed, <1 mm diam., initially green, later dark brown; terminal leaf buds and developing leaves not seen; mature leaves elliptic to oval, sometimes almost oblong to obovate, 24- 27(—32.5) X 10-12(—13) cm, irregularly serrate, occasionally serrations more pronounced proximal­ly, less so distally, adaxially glabrous, mid- to dark green and shiny, abaxially finely and sparsely hairy, lighter green, and dull or slightly shiny, thin, slightly coriaceous, slightly pitted, margins slightly undulate on larger leaves; leaf apex cuspidate, slightly variable, acute on smaller leaves; leaf base obtuse, almost cordate, acute in less developed leaves; midrib narrowly sunken and mid- to light green adaxially, prominent and light green to yellowish green abaxially, less so distally, 2-4(—5) mm wide proximally, <1 mm distally, finely tomentose, with white hairs, not shiny and rather dull; secondary venation pinnate, distinctly brochi- dodromous, with (11 to)14 to 16 pairs of veins, adaxially sunken, indistinct, the abaxial veins more prominent, some veins sparsely tomentose; tertiary venation adaxially rather faint, distinct abaxially; areoles well developed and evenly distributed, with meshes unevenly tetragonal, often oblong, to 0.5-1 X 0.7-1.2 cm, marginally decreasing in size toward leaf margins. Flowers sessile, circular, sometimes unevenly rectangular, terminal, lacking scent; senescing flowers with reflexed, inward curved petals; bracts distinct; flower buds numerous, sessile, in clusters of 9 to 12(to 14), forming a simple umbel-like structure, unevenly orbicular, usually longer than wide; bud scales prominent, terminal, initially dark red with yellow margins, later lighter reddish with areas of yellow pigmenta­tion; bracts prominent, 8 to 10, undifferentiated, persistent on mature flowers, strongly concave, variable in size, 5-13 X 7-15 mm, finely tomentose, finely textured, rigid, and hard, reddish, with margins light yellow, sometimes marginally frayed, striations lacking; sepals 2, distinct, ellipsoid to obovate, 2.5-3 X 1-1.5 cm, persistent, light yellow to green, rigid, finely hairy, also hairy on margins, strongly concave, after anthesis forming a wide and shallow cup; flowers uneven and rectangular, 5-5.5 cm diam., light yellow, rather dull, slightly waxy, hard and rigid; mature flowers with inward folded petal margins; petals 6, arranged in 2 whorls; petals of outer whorl 3, unevenly ellipsoid, obovate, waxy, slightly brittle, thick, slightly thinner on margins, concave, without striations, but internal venation faintly visible on abaxial surfaces, glabrous, without emargination, to 3.5 X 1-2.5 cm, proximally attached to petals of inner whorl for 0.9-1.2 cm; petals of inner whorl 3, unevenly ellipsoid, obovate, waxy, slightly brittle, thick, slightly thinner on margins, concave, without striations, but internal venation faintly visible on abaxial surfaces, gla­brous, without emargination, to 3.3 X 0.9-2.5 cm, proximally attached to filaments for ca. 1 cm; stamens, ca. 100 or more, light yellow, later light brown, in a loose circular formation 2.5-3 cm diam.; filaments light yellow to cream, glabrous, 2-2.5 cm, outer filaments basally attached to inner petals and to each other for ca. 1 cm; anthers 2 X ca. 1 mm, basifixed, longitudinally striate; style single, stout, columnar, proximally wider than distally, apically trifid for 1-2 mm, 2-2.6 cm, light yellow, glabrous; stigma well defined and prominent, 3-lobed, initially yellow, later brown; ovary superior, 5-7 X to 8 mm,1-carpellate, roughly triangular, ridging present, from a 1.5-2.5 mm thick base, yellow, glabrous. Capsules not seen.

Camellia capitata Orel, Curry & Luu.
A. Adult leaf, primary and secondary venation, adaxial view. —B. Adult leaf, primary, secondary, and tertiary venation, adaxial view. —C. Adult leaf, leaf apex variation with primary and secondary venation, adaxial view. —D. Adult leaf, leaf apex variation with primary, secondary, and tertiary venation, abaxial view. —E, F. Adult leaf, leaf base variation with primary and secondary venation, abaxial view. —G. Flower buds. —H. A single flower bud. —I, J. Bracts. —K, L. Sepals. —M, N. Petals, outer whorl. —O, P. Petals, inner whorl. —R. Stamens. —S. Adult gynoecium. —T. Stigma. —U. Lateral view of petal and stamen attachment, schematic diagram. —V. Branch with flowers and leaves. Drawn from the isotype Pham Hong Thai & Nguyen Danh Hiep CT5 (SGN, NSW).

Distribution and ecology

Camellia capitata is known from its type location only, which is situated within the confines of the northern part of the Cat Tien National Park (Cat Loc Sector) in Lam Dong Province, Vietnam. The new species was found in the vicinity of Hamlet 4, Phuoc Cat Commune. Camellia capitata occurs sporadically in small groups of mature plants or as solitary specimens throughout the understory of the evergreen, mixed (broadleaf and bamboo), tropical forest. Camellia capitata thrives in relatively rich, wet, but well-drained soils and in low- light conditions.IUCN Red List category. The AOO of this new species is estimated to be less than 1 km2. Despite a further search of the area around the type locality, only three to five scattered mature plants were located. Given this situation, we consider the IUCN category of Critically Endangered (CR) to be appropriate (IUCN, 2011).

Phenology

Camellia capitata was collected in flower in November. No mature fruit capsules or seeds were evident.

Etymology

The epithet of the new section and species refers to the predominant morphological character, namely the flowers borne in a terminal, headlike structure that may be composed of up to 14 flower buds.