Camellia proensis V.D.Luong, Doudkin & V.H.Quach, 2021

Hoi, Quach Van, Dung, Luong Van, Doudkin, Roman V., Averyanov, Leonid V., Thinh, Bui Bao, Lieu, Nguyen Thi & Truong, Luu Hong, 2021, Camellia proensis (Theaceae, sect. Piquetia), a new species from Southern Vietnam, Phytotaxa 479 (1), pp. 137-141 : 138-140

Camellia proensis V.D.Luong, Doudkin & V.H.Quach , sp. nov. ( Figs. 1 , 2 )

Type:— VIETNAM. Lam Dong Province, Don Duong District, Pro Commune , 800–1100 m elev., 8 March 2015, Quach Van Hoi, Luong Van Dung DUNG.150301 (holotype, isotypes, DLU!) .

Description:— Small tree, 5–6 m tall. Young branches glabrous, light brown buds. Leaves oblong-elliptic, apex acuminate, base rounded or acute, adaxial and abaxial surfaces glabrous, 7.5–8.5 cm wide, 33–35 cm long; petioles 1–2 cm long, glabrous; lateral veins almost parallel, midrib and lateral veins clearly show in the abaxial surfaces, margin denticulate. Flowers 1–3 in the axillary, flower buds globose, 1.3–1.7 cm wide, flower 4.0– 5.5 cm diameter, peduncle branched or not, 3.0– 5.5 cm long, glabrous. Bractlets 2–3, light green, triangular, dropping quickly before the fruiting season, glabrous, 1–2 mm wide 1.5–3.0 mm tall. Sepals 5, hemisphere, persistent, light green, pubescent on the outside, glabrous on the inside, 6–12 mm tall, and 9–15 mm wide. Petals 5–6, almost round to obovate, light yellow, pubescent on the outside, glabrous on the inside, 1.7–1.8 wide and 1.7–2.4 cm tall. Stamens numerous, in 4–5 whorls, 1.5–2.0 cm long, outer filaments basally connate into a tube, filament tube 5–7 mm tall and adnate to the base of petals, pubescent at the base of inner filaments. Ovary globose, tomentose, 3.5–4.0 mm tall and 4–5 mm wide, has grooves, the ovary has 4–5 locular. Styles ripped 4–5 to base, tomentose to ½ from the base, 1.5–1.8 cm long. Fruit flat-globose, 4.0– 5.5 cm tall and 8.5–10.0 cm wide, sparse hair, capsule five locular, 1-locular with two seeds, pericarp 1–1.3 cm thick. Seeds spherical, hemispherical or wedge-shaped, glabrous, 1.6–2.0 cm wide, 2.3–2.6 cm long.

Affinity:— Camellia proensis is morphologically similar to C. sonthaiensis in glabrous young branches and leaves; sepals 5, hairy on the outside; petal light yellow, hairy on the outside, from which it is distinguished by the size of mature fruit, 3.0– 3.5 cm in diameter, 1.5–2.0 cm deep ( C. sonthaiensis ), 4.0– 5.5 cm tall, 8.5–10.0 cm wide ( C. proensis ).

Etymology:— The species is named after the location where the authors first found this plant. Pro is the name of Pro commune, Don Duong District, Lam Dong Province, Vietnam.

Habitat:— This species is distributed in the evergreen broadleaf forest, the foot of the mountain where the slope is low, along the sides of the stream with relatively high humidity, or near the edge of the forest, where there is plenty of light. The species is distributed at elevations 800–1100 m, Pro commune, Don Duong District, Ta Nang Commune, Duc Trong District, Lam Dong Province.

Phenology:— These species produce buds and start to flower from January to March. Flowers bloom in late February, bearing fruits from August to October.

Note:— Camellia proensis has characteristics flowers 1–3 on a short bracteate shoot in axils of old leaves; flowers pedicellate, nodding. Bractlets 2–3, dropping quickly before the fruiting season; sepals 5, persistent; petals 5–6, inter petals united with outermost filaments. Gynoecium superior, ovary 4–5 locular, tomentose; styles 4–5, free. The new species has many characteristics of the section Piquetia (Pierre) Sealy as flowers are borne on a short shoots in the leaves’ axils, usually, 3–5 flowers on a shoot but sometimes one only. Flowers pedicellate, nodding, pedicel very stout, thickened upwards; bracteoles 2–3, persistent; sepals 5, persistent; petals eight or more; stamen free above the union with the petals, puberulous inside; gynoecium densely hairy; styles 5 or 6 (Pierre 1877, Sealy 1958). Therefore Camellia proensis is classified into section Piquetia . Currently, the species in the sect. Piquetia occurring in Vietnam are: C. dalatensis , C. dongnaiensis , C. honbaensis , C. longii , C. piquetiana and C. sonthaiensis (Pierre 1877, Sealy 1958, Orel 2006, Tran & Luong 2012, Orel et al. 2014, Luu et al. 2018). The new taxon is easily distinguishable from C. honbaensis , C. piquetiana and C. longii by the yellow flowers; from C. dalatensis by the glabrous twigs and leaves; from C. dongnaiensis by light yellow flowers; from C. sonthaiensis by mature fruit flat-globose, 4.0– 5.5 cm tall and 8.5–10.0 cm wide.

Figures

FIGURE 1. Camellia proensis. A, B. Young twig. C, E. Flowering shoot and arrangement of petals. D. Open flower. F, G. Fruits. H. Seeds. Photos by Quach Van Hoi.

FIGURE 2. Camellia proensis. A. Leaf. B. Venation of leaf (adaxial surface). C. Venation of leaf (abaxial surface). D. Flower bud. E, F. Flower. G. Sepals. H. Petals. I. Stamens. K. Styles and gynoecium. L. Fruit. M. Seed. Drwaing by Luong Van Dung.