taxonID	type	description	language	source
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	materials_examined	Type: — PHILIPPINES. Luzon Island, Apayao Province, Calanasan Municipality, Brgy. Butao, along Ilocos Norte — Apayao Road, 1350 – 1550 m elevation, 8 December 2023, Dela Cruz 2 (PNH!, holotype, isotype; CAHUP!, isotype). Paratype: — PHILIPPINES. Luzon Island, Apayao Province, Calanasan, Brgy. Butao, along Ilocos Norte — Apayao Road, 1350 – 1550 m elevation, 8 December 2023, Dela Cruz 1 (CAHUP!).	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	diagnosis	Diagnosis: — Vaccinium kilangensis differs from the other Vaccinium species in having one to two-flowered inflorescences with conspicuous foliaceous bracts of which the apical ones form an involucrum around the flowers, white flowers, and small (<2 cm long) elliptic (to narrowly obovate) leaves with an entire leaf margin and obtuse apex.	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	description	Description: — Shrubs, terrestrial, erect, evergreen, densely branched, 1 – 1.5 m tall. Mature branchlets slightly angular, light brown. Internodes of young growth slightly angular, 1.2 – 1.3 mm wide, indumentum of simple trichomes and clavate trichomes, glabrescent, green but youngest parts slightly tinged red. Leaf arrangement spiral, leaves evenly arranged, densely crowded, persistent on older branches. Petioles adaxially flattened and slightly channelled, abaxially rounded, 1.4 – 2.8 × 0.6 – 1.3 mm, margins and adaxial side with simple trichomes, abaxially glabrous, green, tinged red when very young. Leaf blades elliptic (to narrowly obovate), 8.6 – 12.9 × (2.6 –) 4.0 – 7.4 mm, length / width ratio 1.7 – 2.5 (– 3.0), coriaceous, with simple trichomes at the basal part of the midvein, green but tinged red when young, abaxially glabrous and light green; base cuneate; margin entire, revolute, glabrous but with simple trichomes at very base, reddish when young, leaf marginal glands impressed, 1 (or 2) per side, mostly in lower 2 / 3 of leaf; apex obtuse, slightly thickened at ultimate apex; midvein adaxially slightly sunken, abaxially flat; secondary veins faint and sometimes not visible on one or both sides, arching towards apex, 2 or 3 on each side. Inflorescences one per leaf, emerging from perennating buds, axillary but often from axils of apical leaves and therefore appearing terminal and clustered at apex, nodding; peduncles up to 1 mm long; rachises 6 – 12 × 1.0 – 1.1 mm, with simple trichomes and scattered, ca. 0.07 mm long clavate trichomes; 1 or 2 flowers per inflorescence. Inflorescence bracts attached along the entire length of the rachis, basal bracts caducous but apical bracts persistent until after anthesis (and sometimes even persistent when fruiting) and densely imbricate below flowers, conspicuous, foliaceous, elliptic to obovate, relatively flat to cucullate, 3.8 – 6.5 × 1.9 – 2.8 mm, increasing in size towards rachis apex; base attenuate; margin entire, minutely fimbriate when young; apex acute to obtuse; membranaceous, with simple trichomes when young, light green. Flowers 5 - merous. Pedicels ca. 1.3 mm long, with simple trichomes and clavate trichomes. Hypanthia cupuliform, 2.9 – 3.8 × 3.3 – 3.4 mm, glabrescent, sparsely covered with clavate trichomes, green; calyx lobes broadly triangular, 0.4 – 0.6 × 0.8 – 1.8 mm, margin entire and ciliate, otherwise glabrous, terminal gland absent. Corollas broadly conical-urceolate, without sulci or ridges, 3.8 – 5.0 × 5.5 – 6.8 mm, white; corolla tubes 3.6 – 4.5 mm long, outside glabrous or very sparsely puberulent, inside with dense 0.2 – 0.4 mm long trichomes in the central part of corolla tube, but otherwise glabrous; corolla lobes broadly triangular, 0.6 – 0.9 × 0.3 – 0.6 mm, apex obtuse, glabrous. Stamens 10, monomorphic; filaments slightly curved inwards, flattened, 1.2 – 2.2 × 0.4 – 0.7 mm, broadest at base, densely covered with 0.3 – 0.6 mm long white trichomes; anthers 2 – 2.3 mm, light brown, cells cylindrical, but laterally slightly flattened, 0.9 – 1.2 × 0.3 – 0.35 mm, minutely echinulate, spurs perpendicular to anther cells but slightly curved upwards, 0.45 – 0.67 mm, minutely echinulate, tubules parallel to each other, 0.8 – 1 × 0.15 – 0.27 mm, narrower than the anther cells, surface smooth, pores elliptic, slightly oblique. Disk annular, 1.6 – 1.8 mm diam., 0.4 – 0.5 mm high, green, glabrous. Ovaries pseudo- 10 - locular with a false partition in the ovary walls. Ovules in two columns, several per locule. Styles not exerted from corolla, dilated in the middle portion, 3 – 4.3 × 0.5 – 0.9 mm, glabrous, white. Fruits depressed globose, 3.2 – 5.5 × 3.9 – 7.0 mm, black, on 1.1 – 2.5 × 0.9 – 1.1 mm long pedicels that are swollen in their apical half.	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	distribution	Distribution, habitat, and proposed conservation status: — Endemic to the Philippines. Only known from plants at Kilang Pass near Mt. Kilang, which is at the border between the municipalities of Solsona (Ilocos Norte Prov.) and Calanasan (Apayao Prov.) in the northern part of Luzon island near the Ilocos Norte — Apayao Road at 1350 – 1550 m. Although the part of its distribution area in Apayao is included in the yApayaos UNESCO Biosphere Reserve, the area is not recognized as a Protected Area under the National Integrated Protected Areas System (NIPAS). It is presently unknown how large the population at Kilang Pass is and if additional populations exist. We therefore suggest that V. kilangensis should be considered Data Deficient following the IUCN criteria (IUCN Standards and Petitions Committee 2024).	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	etymology	Etymology: — The specific epithet refers to location where the species was collected.	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
03CDC509FFE37A79FF12FD5D8F3EF973.taxon	discussion	Discussion: — Vaccinium kilangensis is one of eight ‘ small-leaved’ Philippine Vaccinium species (sensu Tamayo et al. 2024), which have a leaf lamina of <2 cm long. In contrast to four of these (V. coarctatum M. N. Tamayo & Fernando in Tamayo et al. (2023: 80 - 1960, 2), V. exiguum M. N. Tamayo, R. Bustam. & P. W. Fritsch in Tamayo et al. (2021: 147), V. hamiguitanense P. W. Fritsch in Fritsch et al. (2020: 282), and V. whitfordii), it has an entire leaf margin (Figs 1 D & E). Among the three other small-leaved Philippine species, it is easily distinguished from V. fallax M. N. Tamayo & P. W. Fritsch in Tamayo et al. (2024: 20) and V. microphyllum in flower colour (white vs. pink or red) and its much shorter pedicels (i. e. up to ca. 1.3 mm (to 2.5 mm when fruiting) vs. 5 – 7 mm; Sleumer 1966 – 1967, Tamayo et al. 2024), but it is quite similar in its general leaf morphology. Vaccinium kilangensis is more readily differentiated from V. myrtoides (Blume) Miquel (1859: 1062) when only vegetative features can be observed. It has leaves that are elliptic (to narrowly obovate) (Figs 1 D & E) instead of ovate to oblong-ovate or broadly elliptic and that have an obtuse instead of a gradually attenuate or subacuminate apex (Sleumer 1966 – 1967). However, the inflorescences of V. kilangensis provide the most notable diagnostic characters for this species. It is unique among Malesian Vaccinium in having racemes that bear conspicuous and foliaceous bracts of which only the one or two at the apex subtend a flower. These bracts are long-persistent, particularly those at the apex of the raceme. These are rather densely set and exceed the length of the hypanthium, therefore appearing as an involucrum or epicalyx around the flowers and fruits (Figs 1 A & B). Because its racemes are relatively short (i. e. usually shorter than the leaves) and its peduncles are quite inconspicuous, it may appear that V. kilangensis has solitary flowers, particularly because the racemes are often just producing a single flower (e. g. Fig. 1 A). One could argue that V. kilangensis therefore blurs the distinction between Sleumer’s sect. Oarianthe, which is characterized by its solitary flowers, and sect. Bracteata, which usually has inflorescences with multiple flowers or at least a distinct peduncle (Sleumer 1966 – 1967). However, Becker et al. (2024) concluded that neither section (nor the segregate sections of sect. Bracteata as delimited by Vander Kloet & Dickinson 2009) is monophyletic, and the morphological characters delimiting them might therefore not be informative as indicators of evolutionary relationships among Malesian Vaccinium. Awaiting phylogenetic research with a larger sampling of Malesian species and a monophyletic infrageneric classification for Vaccinium, we therefore here refrain from assigning V. kilangensis to a section. In summary, using morphological distinctiveness with all other Vaccinium species as a ‘ secondary species criterion’ for identifying separately evolving metapopulation lineages, we concluded that V. kilangensis should be considered a distinct species (De Queiroz 2007).	en	Pelser, Pieter B., Cruz, Breiden Dela, Legaspi, Ma. Susana V., Ibañez, Jayson C., Barcelona, Julie F. (2025): Vaccinium kilangensis (Ericaceae), a new species from the border of Ilocos Norte and Apayao Provinces, northern Philippines. Phytotaxa 721 (1): 75-80, DOI: 10.11646/phytotaxa.721.1.4, URL: https://doi.org/10.11646/phytotaxa.721.1.4
