Cyrtandra argentii Olivar, H.J.Atkins & Muellner, 2020

Olivar, Jay Edneil C., Atkins, Hannah J., Hauenschild, Frank & Muellner-Riehl, Alexandra N., 2020, Cyrtandra argentii, a new species of Cyrtandra (Gesneriaceae) from the Philippines, and a review of the C. villosissima group, European Journal of Taxonomy 676, pp. 1-15 : 4-7

Cyrtandra argentii Olivar, H.J.Atkins & Muellner sp. nov. urn:lsid:ipni.org:names:77209562-1 Figs 1 , 2, 3A, 4A

Diagnosis

The species’ pendulous compound cymose inflorescences (10–15 flowers) distinguish it from all other members of the genus in the Philippines. The combination of subequal leaves, white woolly indumentum, glabrous corolla, and ovoid fruit separates this species from the rest of the C. villosissima group.

Etymology

This species is named after George Argent who was part of the team that collected specimens at the type locality. George’s contribution to our knowledge of the Philippine flora is undisputed. His extensive fieldwork in the country has led to the discovery of several new species, recognition of important conservation areas, and promotion of biodiversity studies.

Material examined

Type

PHILIPPINES • Mindoro Island, Oriental Province , Mt Halcon ; 600 m; 13 Mar. 1997; Mendum, M., Argent, C.G.C., Pennington, R.T., Wilkie, P., Reynoso, E.J., Gaerlan, F. 29053 (holotype: E!; isotype: PNH).

Additional material

PHILIPPINES • Mt Halcon, Mindoro ; 12 May 1986; C.E. Ridsdale 1762 (K000223279, L.2822762) • ibid.; 1Apr. 1991; Stone, Reynoso, Sagcal 504 (K000223280, L.2822797, US00737625) • ibid.; 13 Mar. 1997; Argent, Gaerlan , Reynoso 20053 (L.3805692) • Sierra Madre Mountains, Baler Aurora ; 25 Mar. 1968; Jacobs, M. 8002 (L.2822694) • Aurora National Park; 8 Mar. 1993; Barbon, Garcia, Fernando

9121 (K000223281, L.3794225) • Llavac , Infanta, Quezon Province; 25 Jun. 1955; Lagrimas, M. 521 (L.2822646).

Description

An erect suffrutescent plant up to 3 m in height. Stems terete or slightly grooved, with white woolly hairs throughout. Leaves opposite, subequal; petioles 4–7 cm long, densely hirsute; blades 13–30 × 7–15 cm, oblong to oblong-elliptic, slightly falcate, apex attenuate, base rounded to oblique, pronouncedly asymmetrical, not decurrent, margins denticulate, 10–12 pairs of lateral veins, curving and uniting at the margins, densely hirsute on both sides. Inflorescences compound cymes, axillary, pendulous, pedunculate, with 10–15 flowers; peduncle 5–6 cm, densely hirsute; bracts green, ca 9 × 2 mm, lanceolate, densely hirsute on both surfaces, persistent; bracteoles on every point of branching, lanceolate, green, ca 5× 2 mm, densely hirsute on both surfaces; pedicels 3–5 cm long, densely hirsute. Calyx tubular, pale green, ca 15 mm long, upper lobes ca 4 mm long, lower lobes ca 6 mm long, acuminate, densely hirsute externally, glabrous internally. Corolla white, ca 30 mm long, funnel-shaped, lobes suborbicular, upper lobes, 10–12 × 5 mm, lateral lobes 7 × 7 mm, lower lobes 8× 8 mm, 3–4× 1–2 mm; glabrous externally and internally, lobes slightly recurved. Stamens 2; filaments ca 12 mm long, attached ca 17 mm from base of corolla, glabrous; anthers ca 2.5 mm long, thecae parallel, coherent at apices; staminodes 3, lateral staminodes ca 3 mm long, central staminode ca 0.5 mm long. Gynoecium ca 20 mm long overall; disc cupular with entire margin, ca 1.5 mm long, glabrous; ovary ca 6 mm long, glabrous, with some eglandular hairs towards base of style; style ca 14 mm long, with eglandular hairs throughout; stigma bilobed, ca 2.5 mm across. Fruits ovoid, green, glabrous, verrucose, ca 12 × 5 mm, excluding the style; calyx persistent and entirely enclosing the fruit, style persistent.

Distribution and habitat

Cyrtandra argentii sp. nov. is found growing on slopes near streams in primary forests. This species is distributed from the north of Luzon to the island of Mindoro.

Conservation status

Cyrtandra argentii sp. nov. occurs at an elevation of 600–800 m a.s.l. which corresponds to the forest land use zone ( Villanueva & Buot Jr 2018). Using the online GeoCAT conservation assessment tool (http://geocat.kew.org/), the proposed conservation category based on Extent of Occurrence (EOO) is Near Threatened (NT), and the category based on the estimated Area of Occupancy (AOO) calculated using the default 2 × 2 km grid is Endangered (EN). Here, we consider this species’ status as NT due to: i) its occurrence in close proximity to the agroforest land use zone, the latter at approximately 100–400 m a.s.l. ( Villanueva & Buot Jr 2018); and ii) the fact that the forest areas wherein the species occurs are not declared protected by law ( Biodiversity Management Bureau 2015), making it highly susceptible to population decline through deforestation and other anthropogenic activities.

Notes

Like many species of Cyrtandra , filaments of C. argentii sp. nov. recoil into the corolla tube after anther dehiscence. This is hypothesized as constituting a mechanism against self-pollination ( Bramley et al. 2003). The length of the style also varies developmentally, the style can be either exserted or inserted depending on the stage of maturity of the flower.

Figures

Fig. 1. Map of the Philippines showing known distributions of Cyrtandra argentii Olivar, H.J.Atkins & Muellner sp. nov. (*), C. ferruginea Merr. (■), C. hirtigera H.J.Atkins & Cronk (◆), and C. villosissima Merr. (●) based on collection localities. A single point may represent more than one collection.