Psydrax gialaiensis B.H.Quang, T.B.Tran & V.S.Dang, 2020
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publication ID |
https://dx.doi.org/10.3897/phytokeys.149.51710 |
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persistent identifier |
https://treatment.plazi.org/id/AA7F4CBB-CDDB-5258-A9A1-1B94B9488DAC |
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treatment provided by |
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scientific name |
Psydrax gialaiensis B.H.Quang, T.B.Tran & V.S.Dang |
| status |
sp. nov. |
Psydrax gialaiensis B.H.Quang, T.B.Tran & V.S.Dang sp. nov. Figures 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3
Diagnosis.
Differs from all other known species of Psydrax by the strigose pubescence on branches and leaves (vs. glabrous), the conspicuously bulged corolla tube (vs. cylindrical) and the style with a tuft of dense hairs (vs. glabrous).
Type.
Vietnam. Gia Lai Province, Kon Chu Rang Nature Reserve, elevation 989 m, 14°30'50.03"N, 108°32'45.01"E, 19 September 2017, H.Q. Bui, V.H. Do, T.H. Duong, H.S. Doan, D.B. Tran KCR 316 (holotype HN!; isotype HN!, VNM!).
Description.
Shrubs, 2-3 m tall; branches slender, terete, strigose and greyish-brown when dry. Leaves opposite; petioles 3-5 mm long, strigose; blades oblong or elliptic-oblong, 6-12 × 2-3 cm, coriaceous, strigillose adaxially, strigose abaxially, base cuneate to acute, apex acuminate, acumen 8-12 mm long; secondary veins 5-8 on each side of the midrib, conspicuous abaxially, domatia absent. Stipules with long needle-like awn, 4-6 × 2-3 mm, glabrous abaxially and strigose adaxially; sheath 1-1.3 mm long; awn 1-1.5 mm long. Inflorescences 3-6-flowered, pedunculate; peduncle 0.5-2.5 mm long; bracts small, lanceolate, 0.5-0.8 mm long, strigose. Flowers pedicellate; pedicels 7-10 mm long, sparsely strigillose to sub-glabrous; bracteoles absent; flower bud green, apex acuminate. Calyx dark green, sparsely strigillose; calyx lobes 5, triangular, 0.5-1 mm long. Corolla 8.5-10 mm long, greenish, sparse hairs outside; tube conspicuously bulged, 2-2.5 mm long, with a ring of deflexed white hairs inside; lobes 5, oblong or lanceolate, 6.5-7.5 × 2-3 mm, obtuse or subacute at apex. Stamens 5, reflexed; filaments 2-2.5 mm long; anthers oblong, 2-2.5 mm long, white, pubescent. Disc glabrous, 0.8-1 mm in height in flowers, accrescent in fruit, reaching a height of 1-1.5 mm and becoming white. Ovary cupular, c. 4-4.5 mm long, dark green, sparsely strigillose, bilocular, 1-ovule per locule; style and stigma white, style 7.5-8 mm long, exceeding corolla tube for 6-6.5 mm, the middle part of the style with a dense tuft of white hairs; stigma 1 × 0.6 mm, bifid, revealing a cleft at the apex and a slight basal recess. Fruit obovoid, strongly bilobed, 5-6 × 3-4 mm, green to blue green, sparsely strigose, pyrenes 2, cartilaginous. Mature seeds unknown, slightly ellipsoid to oblong, at least 2-3 × 1-2 mm; embryo with cotyledons small, set parallel to the ventral face of the seed.
Other specimen examined.
Vietnam. Gia Lai Province, Kon Chu Rang Nature Reserve, elevation 1000 m, 14°30'50.3"N, 108°32'45.1"E, 20 September 2017, H.Q. Bui, V.H. Do, T.H. Duong, H.S. Doan, D.B. Tran KCR 073 (HN!, VNM).
Phenology.
Flowering and fruiting specimens were collected in September.
Distribution and habitat.
Psydrax gialaiensis is only known from the Kon Chu Rang Nature Reserve, Gia Lai Province, southern Vietnam. It grows in primary evergreen forests, where Pavetta bauchei Bremek., Lasianthus curtisii King & Gamble, Popowia pisocarpa (Blume) Endl. ex Walp., Fissistigma taynguyenense Bân, Ardisia verbascifolia Mez and Litsea clemensii C.K.Allen are dominant.
Etymology.
The specific epithet refers to the type locality, the Gia Lai Province in Vietnam.
Vernacular name.
Căng gia lai
Conservation status.
Psydrax gialaiensis is commonly found in primary evergreen forests in the Kon Chu Rang Nature Reserve where it is well protected. Therefore, we suggest a status of Least Concern (LC) according to the IUCN Red List Categories ( IUCN 2019).
Note.
Psydrax gialaiensis is distinct from the other previously known species of Psydrax in Vietnam based on several characters mentioned in Table 1 View Table 1 .
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