Vitex arvensis Gentallan, Sengun & M. B. Bartolome, 2024

Gentallan Jr., Renerio P., Sengun, Seda, Bartolome, Michael Cedric B., Quiñones, Kristine Joyce O., Coronado, Nadine B., Borromeo, Teresita H. & Timog, Emmanuel Bonifacio S., 2024, The Vitex trifolia complex (Lamiaceae) in the Philippines, PhytoKeys 248, pp. 1-40 : 1-40

1. Vitex arvensis Gentallan, Sengun & M. B. Bartolome sp. nov.

Figs 7 , 8 , 9 , 10 , 11

Vitex leucoxylon Blanco , Fl. Filip. 516. 1837. nom. illeg., not Vitex leucoxylon L. f. Type: Philippines, Rizal, Antipolo, 13 Jan. 1914, Merrill Sp. Blanc. 440 (neotype: L [L. 2768327, designated by Sengun et al. (2024)]).

Vitex negundo var. philippinensis Moldenke , Phytologia 38: 308. 1978. Type: Philippines, Laguna, Los Baños, Apr., 1906, A. D. E. Elmer 8125 (holotype: PNH, destroyed; isotypes: K, NY [NY 00138511]). syn. nov.

Diagnosis.

This new species differs from Vitex elmeri Moldenke by having terminal leaflet which is narrowly elliptic to lanceolate, 4.3–16.0 by 1.0– 3.7 cm, 2.4–5.7 times as long as wide, and with abaxial surface moderately pubescent (vs V. elmeri terminal leaflet narrowly elliptic, 4.0–12.0 by 0.7–3.5 cm, 2.5–8.4 times as long as wide); inflorescence with caducous flowers, leaving a clear set of scars on the axis (vs V. elmeri inflorescence with persistent flowers); fruit 3.0–4.9 by 3.0– 4.3 mm (vs V. elmeri bears 1.8–3.1 by 0.4–0.8 mm fruits fully covered by the calyx at maturity).

Type.

Philippines. Laguna: Los Baños, in the field genebank of the Institute of Crop Science, University of the Philippines Los Baños , 14°09′35″N, 121°14′43″E, 8 Feb. 2019, R. P. Gentallan & M. B. Bartolome 743 (holotype: ICROPS) .

Description.

Shrub to small tree, 2–4 m high. Leaves (1 –) 3–5 - foliolate, reflexed to drooping; terminal leaflet elliptic to lanceolate, 4.3–16.0 by 1.0– 3.7 cm, 3.0–5.0 times as long as wide, terminal petiolules 0–2.3 cm long, moderate olive green (137 B) above, grayish yellow green (191 A to 191 B) below; secondary veins 10–17 pairs; lateral leaflets 3.9–14.5 by 0.9–3.4 cm, 2.4–5.7 times as long as wide, lateral petiolules 0–2.5 cm long, secondary veins 8–11 pairs; basal leaflets when present, 1.9–8.4 by 0.4–3.2 cm, 2.3–4.0 times as long as wide, basal petiolules 0.4–3.2 cm; apex short to long acuminate, base attenuate, acute to short acuminate, or rounded, margin entire, but occasionally dentate when young; abaxial leaf surface sparsely to moderately pubescent, hairs whitish; petiole 2.0– 10.3 cm long, round to tetragonal in cross-section, puberulent. Inflorescence lax paniculate, axis 8.8–23.5 cm long, with primary branch at panicle base and along panicle axis, consisting of lateral cymes in lax clusters attached to the panicle axis or primary branch, with the oldest terminal flower often unfertilized at maturity, angular in cross-section, pubescent; bracteole triangular, up to 2 mm long, apex acute, tomentose. Calyx 5 - lobed, 5 - ribbed; lobes 0.2–1.3 by 0.6–1.25 mm, acute, velutinous; flowering calyx 1.0– 2.49 mm long; fruiting calyx cup-shaped, 3.0– 4.3 mm diameter, covering 1 / 2 to 3 / 4 of the mature fruit. Corolla 5 - lobed, strong violet to light violet (N 88 B to N 88 C), outside covered with appressed hairs; lower lip broadly ovate to orbicular, 2.0–4.5 by 2.4–4.5 mm, apex acute to obtuse, margin entire, often patent, strong violet (N 89 B), yellowish at base, with white and yellowish hairs at corolla mouth; corolla throat inner diameter 2.05–2.53 mm; lateral lobes 1.6–2.1 by 1.6–2.0 mm, apex round to acute, often patent to reflexed, light violet (N 88 C); upper lip 2 - lobed, lobes 1.3–1.7 by 1.4–1.9 mm, apex acute, often patent, light violet (N 88 D); tube infundibular 3.5–4.7 mm long, very pale purple (85 D) to very light purple (85 C). Stamens strongly didynamous, exserted up to 1 / 2 of its length, filaments 2.3–4.3 mm long, inserted 1 / 2 of the way on the corolla tube. Ovary 0.7–1.2 by 0.6–1.2 mm, globose, glabrous; style 3.6–6.6 mm long; stigma lobes 0.4–0.9 mm long. Fruit brown when mature; dried ellipsoid to ovoid, 3.0–4.9 by 3.0– 4.3 mm, apex notched to truncated, glabrous with sparse glands.

Phenology.

Produces fruits and flowers all year round.

Habitat and ecology.

Growing primarily in farmlands, home gardens under cultivation as medicinal and / or hedge article, but recorded in secondary forests, mixed thickets, along rivers, trails and ridges, open places and in wastelands. Altitude: 15– 500 m.

Distribution.

Endemic in the Philippines, distributed primarily from Central to South Luzon but widespread throughout in cultivation.

Vernacular names.

lagundi (Tagalog, Bisaya), dangla (Ilokano, Zambales)

Conservation status.

IUCN assessment gives the extent of occurrence (EOO) and area of occurrence (AOO), as greater than the threshold for the vulnerable category, thus the status would be least concern (LC).

Notes.

1. This taxon has never been recognized at the species level before. The specific epithet arvensis provides insight into its usually cultivated nature since it is primarily cultivated on a commercial scale, and in home gardens as a medicinal plant.

2. This is a putative natural interspecific hybrid between V. bicolor and V. elmeri . Although now distributed across the Philippines, it was primarily distributed in areas where V. elmeri and V. bicolor overlap, from South to Central Luzon. This species bears resemblance to both parents: V. elmeri in terms of the yellow corolla ridge color, presence of villous abaxial secondary veins, sparse pubescence on the lamina undersurface, and having dentate leaves when young; and V. bicolor in terms of lax inflorescence units, flower color, and leaf size.

3. Aside from bearing caducous flowers, this new species further differs from Vitex bicolor Willd. by having the mature ovoid fruits covered by the calyx by 1 / 2–3 / 4 along its length which dries brown, while V. bicolor has larger (5.2–5.8 by 4.3–5.6 mm) globose fruits covered by the calyx to only up to 1 / 5 along its length which dries black.

4. Unlike V. bicolor , V. arvensis was observed to have a lower germination rate of seeds, with virtually non-existent seedlings under the canopy. However, with interventions, these can be germinated ex-situ, albeit with a low success rate.

Documented uses (in the Philippines).

Leaves heated and applied as external patch or as liniment for fever, fruits and leaves used as an insecticide; juice extracted from leaves by grinding ingested for cough relief; decoction or boiling of leaves for fever and cough.

Specimens examined.

Philippines. Cagayan: Peñablanca, San Roque, May 1917, Adduru 173 (US 03805856); Vendivil & Fernando 125366 (PNH); Peñablanca, Callao, Apr 1915, Castillo 22747 (US 03805843); Tuao, May 1979, Sr. M. Rocero 165079 (PNH); Zambales: Botolan, May 1903, Merrill 2917 (US 03805807); Botolan, Villar, Nov 1947, R. B. Fox 4928 (PNH); Bataan: Dinalupihan, Feb 1903, Merrill 1503 (US 03805792); Pampanga: Arayat, Vidal 1648 (L. 2768325); Bulacan: San Miguel, 15–20 m alt., B. Fegan 113564 (PNH); Doña Remedios Trinidad, Kabayanan, Dec 1994, H. Garcia et al. 15334 (L. 4212458); Norzagaray, San Lorenzo, Mar 1996, E. Barbon & H. Garcia 22403 (L. 4216246); Manila: Manila, Oct 1903, Merrill 3429 (US 03805814); Sep 1910, M. Ramos (E 01121257); near Manila, Capt. Wilkes s. n. (US 00830006); Sampaloc, Balic-balic, Aug 1890, Loher 4433 (US 03805840); Mandaluyong, Malamig, G. Edaño 3783 (PNH); Cavite: Mendez, Mangubat 1343 (US 03805791); Laguna: Los Baños, Dec 1903, Hallier 4055 b (L. 2775187); Apr 1906, Elmer 8125 (E 01121256); Sep 1909, Rosenbluth & Tamesis (L. 2768326); 250 m alt., Jan 1911, Holman 99 (US 03805805, US 03805808); Jul 1917, Elmer 18119 (US 03805788, L. 2768218); Makiling National Park, 100 m alt., Oct 1945, M. D. Sulit 8311 (PNH); Mar 1963, D. R. Mendoza 92452 (PNH); San Antonio, Mar 1948, E. Canicosa 9707 (PNH); College, 50 m alt., Sep 1954. J. V. Pancho 32919 (PNH); Batangas: Mataas na Kahoy, Arañez 14 (L. 2768323); Rizal: Marikina, Barangka, G. Edaño 36210 (PNH); Antipolo, 100 m alt., Mar 1903, Merrill 1636 (US 03805812); Jan 1913 Merr. Sp. Blanc. 440 (L. 2768327); Antipolo, Boso-boso, Loher 4432 (US 03805810); San Mateo, May 1904, Ahern’s collector 102 (US 03805809); Taytay, Feb 1953, Lorena 18 (L. 0248373); Tanay, May 1903, Merrill 2320 (US 03805790); Quezon: Tayabas, May 1916, Cailipan 25637 (US 03805789); Infanta, Sep 1904, Whitford 853 (US 03805784); Camarines Sur: Pasacao, Dalupaon, 1901, Ahern 255 (BO 1616593, US 03805779), Naga City, Mt. Isarog, Oct 1992, Barbon et al. 8377 (L. 3930320); Agusan Norte: Butuan City, Tungao, May 1991, Barbon et al. 1917 (L. 4212463).

Figures

Figure 7. Vitex arvensis A habit B part of inflorescence C side view of flower D calyx open, adaxial E Corolla open F style fruit in G calyx H fruit in cross-section I calyx. Illustration by Daryl Ceribo. Scale bars: 2.5 cm (A, B); 1 cm (C), 1 mm (D, E, F, G, H, I).

Figure 8. Morphological characteristics of V. arvensis A branch with inflorescence B sixth fully unfolded leaf C abaxial leaf lamina surface D – F flower G inflorescence unit H – I mature fruit with and without calyx.

Figure 9. Leaf undersurface pubescence of V. arvensis (40 × magnification). Photos: L. E. Endonela.

Figure 10. Natural distribution of Vitex arvensis in the Philippines.

Figure 11. Holotype specimen of Vitex arvensis.