Wednesday, November 6, 2024

[Botany • 2024] Vaccinium fallax, V. gamay & V. vomicum • Three New Species of Vaccinium L. (Ericaceae: Vaccinieae) from Mindanao Island, Philippines


Vaccinium fallax M.N.Tamayo & P.W.Fritsch,

in Tamayo, Amoroso, Coritico, Penneys, Callado, Horner et Fritsch, 2024.
 
Abstract
Three new species of Vaccinium endemic to the island of Mindanao, Philippines are here described and illustrated. Vaccinium fallax most closely resembles V. myrtoides, but differs by having smaller leaves, caducous bracts, shorter pedicels, a broadly obconical hypanthium, broadly triangular calyx lobes, and a deep pink and broadly urceolate corolla. It grows on exposed areas and among sulfur vents at and near the summit of Mt. Apo. Vaccinium gamay most closely resembles V. gitingense, but differs in having shorter inflorescences, early caducous inflorescence bracts, shorter pedicels, presence of clavate glands on the hypanthium, and an absence of anther spurs. It grows on exposed areas in the ultramafic forest of Mt. Hamiguitan. It is one of only two Philippine Vaccinium species possessing distinctly callose-thickened calyx lobes, the other being V. gitingense. Vaccinium vomicum most closely resembles V. carmesinum, but differs by having smaller leaves, presence of glands on the extreme end of the leaf blade base, presence of clavate glands on the hypanthium, shorter stamens, and presence of stalked glands on the dentate apex of the tubules. It grows in the mossy rainforest of Mt. Kitanglad, and it is the only Philippine species of Vaccinium with glands on the extreme end of its leaf blade base. Following IUCN guidelines, we propose a conservation status of Critically Endangered for V. fallax, Endangered for V. gamay, and Data Deficient for V. vomicum. With these discoveries, the number of Vaccinium species in Mindanao Islands increases to 22 and in the Philippines to 44. Furthermore, the Mindanao Islands can now be considered the center of Vaccinium diversity in the Philippines.

Key words: blueberries, Malesia, sulfur vents, taxonomy, ultramafic soils, Vaccinieae

Vaccinium fallax.
A. Summit area of Mt. Apo showing a vent spewing sulfur fumes. B & C. Flowering branchlet in vivo. D.Flowering branchlet showing pedicel, hypanthium, and calyx lobes.
Photos B–D from PLSPH 3735; photos by P.W. Fritsch.

Vaccinium fallax M.N.Tamayo & P.W.Fritsch, sp. nov.  

Diagnosis:—Vaccinium fallax most closely resembles V. myrtoides (Blume 1826: 861) Miquel (1859: 1062) but can be distinguished by having smaller leaves [0.7–2.0 × 0.25–1.0 cm vs. 1.3–2.0 (–2.5) × (0.6–) 0.7–1.3 (–1.8) cm], caducous bracts (vs. partly persistent), shorter pedicels [0.5–0.7 cm vs. 0.5–1(–1.4 cm)], a broadly obconical hypanthium (vs. cupuliform), broadly triangular calyx lobes (vs. triangular), and a deep pink (vs. pale pink) and broadly urceolate corolla (vs. narrowly cylindric-urceolate).

Etymology:—The epithet “fallax” is Latin meaning deceptive. This is in reference to its close morphological resemblance to Vaccinium myrtoides.

Vaccinium gamay.
A. Fruiting branchlets in vivo. B. Fertile branchlets with flower buds and flowers in full anthesis. C. Lateralview of inflorescence. D. Fertile branchlet showing flowers in full anthesis and immature infructescence. E. Longitudinal section of flowershowing stamens and style.
 All from J.R.C. Callado 2633; photos by J.R.C. Callado. 

Vaccinium gamay M.N.Tamayo & P.W.Fritsch, sp. nov.  

Diagnosis:—Vaccinium gamay most closely resembles V. gitingense Elmer (1912: 1490) but is distinguished by having shorter inflorescences (3–4 cm vs. 4–6 cm), early caducous inflorescence bracts (vs. persistent), shorter pedicels [8–9 mm vs. (7–)10–15 mm], presence of clavate glands on the hypanthium (vs. absence), and an absence of anther spurs (vs. presence).

Etymology:—The epithet “gamay” is a Cebuano word meaning small. This refers to the relatively small and dainty flowers of the new species.


Vaccinium vomicum M.N.Tamayo & P.W.Fritsch, sp. nov. 

Diagnosis:—Vaccinium vomicum most closely resembles V. carmesinum M.N.Tamayo & P.W.Fritsch (2020: 174) but differs by having smaller leaves (5.0–9.0 × 1.8–5.2 cm vs. 7–15 × 0.4–9 cm), the presence of glands on the extreme end of the leaf blade base (vs. ca. 1–2 cm from the leaf blade base), the presence of clavate glands on the hypanthium (vs. absence), shorter stamens (4.5–5.5 mm long vs. 5.5–7.2 mm long), and the presence of stalked glands on the dentate apex of the tubules (vs. glandless, entire)

Etymology:—The epithet “vomicum” is Latin meaning abscess or sore. This is in reference to the conspicuous pair of glands on the extreme end of the leaf base of this species.


 Maverick N. Tamayo, Victor B. Amoroso, Fulgent P. Coritico, Darin S. Penneys, John Rey C. Callado, John D. Horner and Peter W. Fritsch. 2024. Three New Species of Vaccinium L. (Ericaceae) from Mindanao Island, Philippines. Phytotaxa. 647(1); 19-33. DOI: doi.org/10.11646/phytotaxa.647.1.2