taxonID	type	description	language	source
E01F4A57422E56A2A7300172AC5BC43C.taxon	description	Fig. 1	en	Nguyen, Hieu Cuong, Nguyen-Le, Xuan Bach, Nguyen, Quoc Dat, Nguyen, Tran Quoc Trung, Luu, Hong Truong (2024): Xanthophytum antoanense (Rubiaceae, Ophiorrhizeae), a new species from Vietnam. PhytoKeys 250: 215-222, DOI: 10.3897/phytokeys.250.137482
E01F4A57422E56A2A7300172AC5BC43C.taxon	diagnosis	Diagnosis. The new species is morphologically closest to X. capitatum Valeton but differs from the latter by its 3 - lobed (vs. unlobed) stipules, narrowly lanceolate (vs. oblong to obovate) leaf blades with a cuneate-oblique (vs. symmetrically cuneate to attenuate) base and 20 – 22 (vs. 11 – 16) pairs of secondary veins, 3.5 – 4.5 (vs. 0.5 – 3) cm long peduncle, spatulate (vs. bluntly triangular) calyx lobes, larger flowers with a 5 – 5.4 (vs. c. 1.8) mm long corolla tube and 2.4 – 3 (vs. c. 0.7) mm long corolla lobes, and an apically hairy (vs. glabrous) style.	en	Nguyen, Hieu Cuong, Nguyen-Le, Xuan Bach, Nguyen, Quoc Dat, Nguyen, Tran Quoc Trung, Luu, Hong Truong (2024): Xanthophytum antoanense (Rubiaceae, Ophiorrhizeae), a new species from Vietnam. PhytoKeys 250: 215-222, DOI: 10.3897/phytokeys.250.137482
E01F4A57422E56A2A7300172AC5BC43C.taxon	description	Description. Monocaul dwarf shrublet, sub-herbaceous, to 50 cm tall. Stems densely hairy, hairs septate, red, c. 1 mm long. Leaves simple, opposite, decussate; petiole 4 – 6 cm long, c. 0.35 cm in diameter, densely hairy with hairs septate, red, c. 1.5 mm long; lamina elongate-lanceolate, 13 – 24 cm long, 3 – 4.5 cm wide, adaxially green, glabrous, abaxially gray, densely hairy, hairs setose, red, c. 1.5 mm long; base cuneate-oblique, apex acute; venation pinnate, midrib prominent on both surfaces, adaxially sparsely and abaxially densely hairy, hairs c. 1.5 mm long, secondary veins 20 – 22 pairs, weakly brochidodromous, tertiary veins abaxially prominent. Stipules 1.7 – 2.5 cm long, 1.2 cm at widest, ovate, acuminate, slightly 3 - lobed, abaxially densely hairy, hairs septate, red, c. 1.5 mm long. Inflorescences axillary, pseudo-terminal heads, erect then nodding, heads c. 2 cm in diameter, many-flowered; peduncles 3.5 – 4.5 cm long, 0.2 – 0.3 cm in diameter, densely hairy, hairs septate, red, c. 1.3 mm long. Bracts oblanceolate, 3.0 – 3.2 mm long, 1.1 – 1.3 mm wide, white, apically red-violet, ciliate, abaxially densely hairy, hairs septate, red, c. 1 mm long. Interfloral bracts linear, c. 3.5 mm long, 0.25 mm wide, white, abaxially densely hairy, hairs septate, red, c. 0.6 – 0.8 mm long. Flowers bisexual, probably heterostylous, sessile, c. 1.1 cm long. Calyx 5 - lobed, lobes spatulate, white, apically red, 7 – 8 mm long, c. 1.6 mm at widest, adaxially glabrous, abaxially densely hairy, hairs septate, red, c. 1 mm long. Corolla white, turning brown, tubiform with spreading lobes; tube 5 – 5.4 mm long, 1.2 – 1.4 mm in diameter, outside glabrous, inside densely white tomentose on upper ¾, hairs 0.4 – 0.5 mm long; lobes 5, 2.4 – 3 mm long, 0.7 – 1 mm at widest, oblong-lanceolate, acute, outside white to red setose with 0.5 – 0.6 mm long stiff hairs, inside papillose. Stamens 5, inserted at corolla base, 5.3 – 5.5 mm long; filaments c. 5 mm long, glabrous; anthers c. 1 mm long, dorsifixed, longitudinally dehiscent. Pistil 4.8 – 5.0 mm long; disc white, hemispherical, c. 0.5 mm high; ovary 2 - celled, c. 2 mm high, 1.5 mm wide, densely red septate hairy; ovules numerous on a globose, axile placenta in each cell; style 2.7 – 2.8 mm long, gradually thickened towards the apex, sparsely hairy on upper half; stigma 2 - lobed, lobes lanceolate, with obtuse apex, c. 1.3 – 1.4 mm long. Fruit unknown.	en	Nguyen, Hieu Cuong, Nguyen-Le, Xuan Bach, Nguyen, Quoc Dat, Nguyen, Tran Quoc Trung, Luu, Hong Truong (2024): Xanthophytum antoanense (Rubiaceae, Ophiorrhizeae), a new species from Vietnam. PhytoKeys 250: 215-222, DOI: 10.3897/phytokeys.250.137482
E01F4A57422E56A2A7300172AC5BC43C.taxon	etymology	Etymology. The species epithet is derived from the location where the new taxon was discovered.	en	Nguyen, Hieu Cuong, Nguyen-Le, Xuan Bach, Nguyen, Quoc Dat, Nguyen, Tran Quoc Trung, Luu, Hong Truong (2024): Xanthophytum antoanense (Rubiaceae, Ophiorrhizeae), a new species from Vietnam. PhytoKeys 250: 215-222, DOI: 10.3897/phytokeys.250.137482
E01F4A57422E56A2A7300172AC5BC43C.taxon	distribution	Distribution and ecology. The species is known only from An Toan Nature Reserve (Binh Dinh Province, Vietnam). It grows on moist fertile soils in lower montane evergreen forests at elevations around 850 m. The forest is dominated by Rubiaceae, Fagaceae, Lauraceae, Myrtaceae, Clusiaceae, and Fabaceae.	en	Nguyen, Hieu Cuong, Nguyen-Le, Xuan Bach, Nguyen, Quoc Dat, Nguyen, Tran Quoc Trung, Luu, Hong Truong (2024): Xanthophytum antoanense (Rubiaceae, Ophiorrhizeae), a new species from Vietnam. PhytoKeys 250: 215-222, DOI: 10.3897/phytokeys.250.137482
