Brassaiopsis gigantea J.Wen & Lowry, 2006

Wen, Jun & Lowry Ii, Porter P., 2006, New species and new combinations in Brassaiopsis (Araliaceae) from Vietnam and southwestern China, Adansonia (3) 28 (1), pp. 181-190 : 187-189

Brassaiopsis gigantea J.Wen & Lowry , sp. nov.

( Fig. 3 )

Arbor . Folia chartacea, 15-35 cm longa, 15-30 cm lata, lobis 5-7, marginae serratis. Panicula terminalis 30-35 cm longa, stellato-pubescens; umbellate 17-25-florae, pedicellis 8-20 mm longis. Ovarium biloculare, stylis connatis.

TYPUS. — Vietnam. Ninh Binh Prov., Cuc Phuong National Park , primary forest, 105°34’13.2”E, 20°22’54.0”N, 200 m, 28.VIII.2000, fl ., N. M. Cuong, D . T. Kien & M.V. Sinh 1068, tree 6 m tall, dbh 49 cm, bark gray, flowers dull white (holo-, F!) .

PARATYPES. — Vietnam. Ninh Binh Prov., Cuc Phuong National Park , near headquarter, 20°14’59.5”N, 105°42’55.9”E, 150 m, 1. I .2002, ster., J. Wen, N. T . Hiep & N. M . Cuong 6118 ( F!, HN!). — Nho Quan District, Cuc Phuong National Park, hotspot 33, 11 km from Bong , primary forest on steep limestone slope, 20°17’21.0”N, 105°40’16.8”E, 315 m, 25. V .2000, ster., D.D. Soejarto & N. M . Cuong 11614 ( F!). — In reservato Cuc Phuong, 400 m, V .1965, fr., Ng. Anh Tiep s.n. ( P!) .

DESCRIPTION

Tree 6-12 m tall, dbh 10-50 cm, andromonoecious, stem gray, with conical prickles 3-6 mm long. Leaves simple, 5-7-lobed, the sinuses reaching to c. 2/3 to the base, stipules adnate in lower 1/2 to the petiole, free portions lanceolate, 5-6.5 mm long, 1-1.2 mm wide, pubescent and subcoriaceous, leaf blade 15-35 cm long, 15-30 cm wide, papyraceous to thickly so, stellate above, densely stellate below, lobes elliptic to ovate, (7-) 10-20 cm long, 6-11 cm wide, primary veins 5-7, secondary and tertiary veins prominent on both surfaces, base cordate, margin serrate to sparsely so in apical 3/4, the teeth 1-2 mm long, entire in basal 1/4, apex acuminate; petiole 15-30 cm long, stellate. Inflorescence an upright terminal panicle, unarmed, stellate, primary axis 30-35 cm long, secondary axes 9-10, 15- 22 cm long at anthesis, each bearing a terminal umbel of bisexual flowers and 2-6 lateral umbels of apparently mostly bisexual and male flowers, terminal umbel 3.7-4.2 cm diam., with 20-25 flowers, peduncles of the lateral umbels 1-3 cm long, lateral umbels 1.7-2 cm in diam. in bud, with 17-20 flowers; bracts persistent, sometimes with 1-2 small lobes at the lower or middle part, coriaceous and pubescent, narrowly triangular, 6- 10 mm long, 2.5-3 mm wide; pedicels inarticulate, densely stellate, 8-20 mm long; bracteoles subtending pedicels lanceolate, 3-4.5 mm long, 0.8-1.2 mm wide, persistent. Floral buds conspicuously angular in appearance. Sepals 5, triangular, 0.7-0.9 mm long, 0.8-1 mm wide, petals 5, ovate-triangular, 3.5-4 mm long, 2-2.5 mm wide, stamens 5, filaments 3-4 mm long, anthers oblong, 1.3-1.5 mm long, c. 1 mm wide, ovary 2-locular, styles united, stigmas inconspicuous, disc slightly projected. Fruits ellipsoid to slightly obovoid, 6-7 mm long, 4.4-6 mm in diam.

REMARKS

Brassaiopsis gigantea has the largest girth of any member of the genus, forming trees to 12 m in height, with a trunk that can reach 50 cm dbh. It resembles B. grushvitzkyi J.Wen, Lowry & T.H.Nguyên of southwestern China and northern Vietnam in its tree habit, stellate leaf pubescence, and coriaceous inflorescence bracts, but differs in its serrate or sparsely serrate (vs. entire) leaf margin and bilocular (vs. 5-locular) ovary (also see Wen et al. 2003). Brassaiopsis gigantea can be distinguished from B. phanrangensis Shang from north-central Vietnam in having leaves that are densely stellate on both surfaces (vs. glabrous above and sparsely short tomentose to stellate below, especially along the veins) and papyraceous to thickly papyraceous (vs. thin chartaceous), and inflorescences that are stellate throughout at anthesis (vs. glabrescent except at the nodes of the inflorescence axes and umbels, which are densely lanate at anthesis, then almost glabrescent in fruit) with stellate (vs. densely lanate) bracts. Brassaiopsis gigantea can be easily distinguished from B. stellata K.M.Feng of southwestern China and northern Vietnam by its robust and upright (vs. slender and drooping) inflorescence and 5-7-lobed (vs. mostly 3-5-lobed) leaves, as well as its arborescent (vs. shrubby) habit.

DISTRIBUTION

Known only from Ninh Binh Province in northcentral Vietnam; 150-400 m.

PHENOLOGY

Flowering in late August, fruiting in May.

Figures

FIG. 3. — Brassaiopsis gigantea J.Wen & Lowry:A, leaf and erect terminal inflorescence; B, terminal umbel;C, portion of inflorescence axis showing a bract with a small lobe in the lower part; D, floral bud; E, flower just prior to anthesis; F, flower after anthesis showing projected ovary; G, stem with base of petiole showing stipule; H, young branch showing prickly stem. Cuong et al. 1068. Scale bars: A, 5 cm; B, 3.5 cm; C, G, 1 cm; D, 3 mm; E, F, 4 mm; H, 2 cm.