Priogymnanthus colombianus Fern.Alonso

Fernández-Alonso, José Luis & Morales, Paula Andrea Morales, 2019, Priogymnanthus colombianus (Oleaceae), a new species and first record of genus to Colombia, Phytotaxa 399 (3), pp. 195-202 : 196-201

Priogymnanthus colombianus Fern.Alonso & P.A. Morales-M., sp. nov. (Figure 1,2,3)

Type:— COLOMBIA. Antioquia. Municipio de Sonsón, Vereda Naranjal Abajo, borde de quebrada Magallo cerca de su desembocadura en el Rio Aures , 1213 m, 19 oct 2017 (fl), Morales P. 1230 (Holotype HUA-211572; Isotypes: HUA!, COL!, JAUM!, MA!, MO!) .

It resembles Priogymnanthus apertus (B. Sthal) P.S. Green by leaves oblong-elliptic and glabrous, but differs in longer petioles (10–19 mm vs. 5–10 mm), longer inflorescences ((15) 18–25 mm vs. 15–19 mm), petals linear-lanceolate of 4–5 mm long vs. petals narrowly elliptic, 2 mm long, shorter anthers (3 mm vs 3–4 mm), and smaller globose fruits (10–15 × 11–14 mm vs. obpyriform fruits, 20–25 × 17–20 mm).

Trees semideciduous, 8–13 m tall and 15–30 cm diameter at breast height; bark slightly rugose, brown-reddish; branches glabrous when old, with conspicuous lenticels, terminal axis dorsally flattened; internodes (1.5) 2–3 cm long; nodes slightly thickened. Leaves opposite (rarely subopposite), simple, mainly disposed in distal portion of branches; petiole 10–17(19) × 1.5–2 mm, slightly grooved, yellowish in live plants and blackish when dry; blade (7)8–13 × (3.5)4.5–5.5(6) cm, chartaceous, oblong to oblong-elliptic, base cuneate to attenuate, apex acute to acuminate (rarely obtuse), margin entire but slightly sinuate in dry specimens, both surfaces glabrous, shiny in adaxial side; venation pinnate, midrib yellowish, immersed above and prominent below, secondary veins of 8–10 (11) pairs and slightly flattened, tertiary venation slightly conspicuous adaxially and less abaxially; domatia and stipules absent. Inflorescence axillary or terminal (subterminal), cymose, frequently 1–3 on nodes (usually leafless) before the inferior pair of leaves. Young inflorescence 4–7 × 4–5 mm, compactly bracteate, ovoid to conic; cataphylls (2.5)3–5 × 2–5 mm, 5–6 pairs, triangular, concaves, decussate, coriaceous, shiny, green or blackish with reddish margins, covered by white finely lanate indumentum (yellowish when dry), mainly at base and margins. Elongated Inflorescence (15)18–25 × 8–10 mm, 7–9(11) flowers in 4–5 cymes of one pair of decussate flowers, except the last one with 3 flowers; peduncle ca. 1 mm, cylindrical, with 1–2 pair of dry cataphylls followed by 2 basal bracts 2.5 × 2.0 mm, connate, narrowly triangular, green with reddish margin; rachis glabrescent, pale green, 1–4 pair of cataphyll remaining dry basally; floral bracts 2 × 1 mm, membranous, elliptic, concave, promptly deciduous leaving visible scars, green, whitish lanate indumentum in both surfaces. Flowers bisexual; pedicels (1) 2–3 mm long during anthesis, glabrous; calyx absent; petals 4–5 × 1 mm, white, alternate with statements, promptly caducous, linear-lanceolate, apex acute, puberulous above and beneath, margin ciliate, stamens 4, ca. 4 mm long, 2-sporangiate, 4-thecate, white yellowish before dehiscence, brown after that, sometimes alternating opened and closed, filament thick, 1 × 0.5 mm, connective inconspicuous, anther ca. 3 × 0.8 mm, botuliform, slightly arched towards floral axis, falcate after dehiscence; pistil 3 mm long, glabrous, green, ovary 1 mm diameter, superior, 2-locular, style ca. 1.2 mm long, cylindrical, stigma 0.8–1 mm long, deltoid with 2 terminal and flattened lobes. Infructescence with 1–3 developed fruits but until 20–30 per terminal branch; peduncles ca. 8–11 × 1.5 mm, slightly thickened on distal portion, lenticelate, green. Fruits (10)12–15 × 11–14 mm, drupes, globose, slightly narrowed at base with an apiculum distally, glabrous, green; pericarp olive green with sparsely minute white spots, black-bluish when dry and finely tuberculate surface with pruinose aspect; pyrene 8–12 mm diameter, globose, brown, free of pericarp with a space of 1–2 mm when mature with a basal rounded scar, smooth surface with 4 longitudinal striates. Seed is rounded with a white nut inside.

Etymology: —The specific epithet refers to the country of origin for the known collections of this species.

Vernacular name and uses: —Cerezo. Timber species and feeding for animals like squirrels.

Phenology: —According to Priogymnanthus colombianus specimens and phenological record, this species is flowering from April to October and fruiting from November to February. After flower pollination ripening of fruits takes at least two months

Distribution and habitat: — Priogymnanthus colombianus is distributed in Colombia with only three records from the departments Antioquia and Tolima. It occurs in in the Cauca Valley between the western slope of Cordillera Central and the eastern slope of Cordillera Occidental, as well as areas close to Magdalena Valley on the western slope of Cordillera Oriental in the Colombian Andes ( Figure 4 ). It seems to thrive in the transitional zone from premontane forests to dry forest, at elevations between 719–1213 m. The Antioquia population grows on very steep and rocky soil on the humid banks of a creek.

Conservation status:— The main threat to this species is unsustainable harvesting of timber. Its wood has been frequently used and is valued by locals in Sonsón. They suggested that it was more frequent in the forest a couple decades ago (Montoya pers. comm.). Historic deforestation and the associated loss of habitat in ecosystems like dry forest and premontane forest in Colombia due to mining, livestock and agriculture, threaten conservation efforts for Priogymnanthus colombianus in its extent of occurrence. Deforestation data across dry forest ecosystem in Colombia indicate that the potential range for this species in this ecosystem has decreased by 90% by the end of the 20th century ( Pizano & Garcia 2014).

Up to date there are only three records, all of them in non-protected areas in forest fragmented and disturbed inside transitions between premontane humid forest and tropical dry forest. More field work is needed to check for undetected populations in similar conditions, like in Argelia, Antioquia (Montoya pers. comm.).

After analyzing the Red List parameters obtained in ConR: EOO of 3406 km 2, only three locations and subpopulations, any subpopulation inside protected areas, and evaluated current threats, potential distribution and potential habitat available for this species, Priogymnanthus colombianus , is categorized as Endangered (EN), according to B1ab(ii)b(iii) IUCN Red List Criteria ( IUCN 2012).

Taxonomic relationships: — Priogymnanthus colombianus can be recognized by the following character combination of leaves oblong or oblong-elliptic, chartaceous, entirely glabrous, petioles 10–17(19) mm, inflorescences (15) 18–25 mm with glabrescent axis, anther about 3 mm long and relatively small fruits (10)12–15 × 11–14 mm. It differs from P. hasslerianus (Chodat) P.S. Green by blade shape (elliptic-ovate) and consistency (coriaceaus), longer petiole (15–30 mm). P. apertus (B.Ståhl) P.S.Green differs by shorter petioles (5–10 mm), shorter petals (2 mm), longer anthers (3–4 mm) and longer fruits (20–25 mm). P. saxicolus Lombardi diverge by smaller elliptic leaves (4–9 cm), shorter petioles (6–9 mm) and persistent villose indumentum on abaxial blades and inflorescences of smaller size (7 × 7 mm) with sessile anthers and thicker pistil.

Paratypes: COLOMBIA. Antioquia. Municipio de Sonsón, Vereda Naranjal Abajo , borde de quebrada, 1213 m, 19 November 2017 (fr), P. Morales 1231 (HUA-211573, JAUM) ; Antioquia. Municipio de Buriticá, Vereda Higabra , 719 m, 1 st March 2017 (fl, fr), Herrera M. 14 (HUA-208683) ; Tolima. Municipio de Dolores, Vereda Los Guásimos, Finca San Miguel , 842 m, 16 April 1980 (fl), R. Echeverry 3439 (COL-217753) .

Other Priogymnanthus specimens examined:— Priogymnanthus apertus : ECUADOR. Prov. El Oro: Zaruma, Portovelo (gold mine near Zaruma ), 600–1000 m, 30 August–1 September 1923, (fl, fr), A. S. Hitchcock 21223 (Holotype, NY-00039610) ; Ibidem: 60 Km SE of Arenillas, along road to Loja, ( Dry zone, steep slopes with forest along the rivers), 400 m, 13 November 1982, (fr), T. D. Pennington & G. Tenorio 10722 (QCA-162958) ; Prov. Manabi: San Sebastian , 400–550 m, 16 October 1992, (fl, fr), n. v. Francisco ; Josse et al. 839 (QCA-162962). Priogymnanthus hasslerianus : BOLIVIA. Santa Cruz: Prov. Angel Sandoval, alrededores de San Fernando , 16 October 2001, J. C. Catari et al. 146 ( MO) . PARAGUAY. Ad ripamrivi Salado , September 1898 –1899, (fl), E. Hassler 3240 (Holotype G00381135 ; Isotype G00381136 , Isotype BM000021533 , Isotypus P00753776 ) ; Central: in regione lacus Ypacaray , August 1913, E. Hassler 11889 ( C, MO) .

Figures

FIGURE 4. Priogymnanthus colombianus occurrence map and main IUCN parameters.