Curarea gentryana R.Ortiz, 2018

Ortiz, Rosa del C., 2018, A taxonomic revision of Curarea Barneby & Krukoff (Menispermaceae), PhytoKeys 100, pp. 9-89 : 36-38

5. Curarea gentryana R.Ortiz sp. nov. Fig. 19

Diagnosis.

The species is distinguished from its congeners by its staminate flowers with the lateral margins of inner petals adaxially connate or connivent, also by its large broadly obovoid or ellipsoid drupelet that has a silvery tomentellous indumentum.

Type.

Ecuador. Esmeraldas: San Lorenzo Canton, Reserva Indígena Awá, Parroquia Ricaurte , Comunidad Balsareno , Rio Palabi , bosque muy húmedo tropical, bosque primario, disturbado, 01°09'N; 078°31'W, 100 m, 15-29 Apr 1991, (♂ fl), Rubio & Quelal 1503 (holotype: MO!; isotypes: NY!, QCNE!) .

Note.

The earlier listing of the name in Ortiz-Gentry (2000) does not constitute effective publication as per article 30.8 of the Melbourne Code ( MacNeill et al. 2012), and is therefore here being validated.

Description.

Medium-sized understory lianas ca. 8 m tall, older stems more or less terete, 0.5-1 cm diameter, bark dark brown, with shallow lengthwise fissures and conspicuously tuberculate-lenticellate; branchlets brownish strigillose-tomentellous to glabrate. Leaves: blades 17-22 × 14-23 cm; broadly ovate, base truncate or weakly cordate, apex acuminate, cuspidate when juvenile; chartaceous when mature or when exposed to direct sunlight, otherwise membranous; surfaces discolorous, lustrous and glabrous adaxially, finely silvery web-like abaxially, indumentum concealing the surface, persistent at all stages; 5-palmatinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib and lateral nerves slightly raised to weakly sunken adaxially, conspicuously raised abaxially, secondary veins 2(3) pairs, arising above the middle of the blade, veinlets raised on both surfaces; petioles 11.3-16.9 cm long, ridged, silvery or brownish strigillose-tomentellous to glabrate, weakly pulvinate at both ends, apical one conspicuous, rugulose. Staminate inflorescences fascicled, axillary or cauliflorous, lax thyrsi (Fig. 19A-B ), silvery or brownish strigillose-tomentellous to glabrate; axes ca. 7.6 cm long; primary branches ca. 4 cm long, with several (2-5) orders of cymose branching, less frequently the higher branch orders are reduced on alternating sides, appearing racemiform; bracts ca. 1.1 mm long, lanceolate, concave, fleshy, indumentum as on inflorescence. Pistillate inflorescences unknown. Staminate flowers ca. 1.3 mm long, cream; pedicels ca. 0.7 mm long, terete, indumentum as on inflorescence; bracteoles 1-2, ca. 0.2 × 0.2 mm, ovate or oblong, fleshy, glabrous adaxially, silvery tomentellous abaxially; sepals 6, glabrous adaxially, silvery tomentellous abaxially; outer sepals ca. 1 × 0.6 mm, narrowly ovate or ovate-rhombic, base obtuse to truncate, apex acute or obtuse; inner sepals ca. 1.6 × 0.9 mm, obovate or weakly rhombic, base obtuse to cuneate, apex acute to obtuse, tip of inner sepals erect to strongly reflexed at anthesis; petals 6, ca.0.8- 0.9 × 0.4-0.5 mm, narrowly obovate-trilobed to strongly spatulate, the latter the more so when there are only three stamens, moderately concave, membranous, glabrous adaxially, glabrous or sparsely silvery tomentellous abaxially, base cuneate or strongly clawed, lateral margins strongly inflexed, partially clasping the filaments and sometimes the inner ones are adaxially connate or coherent, when 3 stamens are present, apex rounded to slightly retuse or truncate; stamens 3(-6), 1(2)-whorled, filaments ca. 0.6 mm long, clavate, free (or variously connate when 4-6), glabrous; anthers ca. 0.3 mm long, erect, connective adaxially thicker, sometimes forming a keel at the base of the anthers, apically overgrowing thecae and forming a hump when older (Fig. 19H ). Pistillate flowers unknown. Infructescences axes ca. (1.3)3.5 × 0.3-0.4 cm, conspicuously lenticellate, strigillose-tomentellous or glabrate; fruiting pedicels (in immature fruits) 4.7-6.3 mm long, terete; carpophores 2.5-3.1 mm long, terete in immature fruits, not seen in mature fruits, truncate at apex, velutinous. Drupelets 3.6-4.6 × 2.1-2.8 cm, (colour when ripe unknown), weakly obovoid or ellipsoid (Fig. 19I ), weakly eccentrically attached, base obtuse, stylar scar not apparent; exocarp ca. 2.6 mm thick, surface rugose, sparsely brownish velutinous tomentellous or glabrate, granular when dried; mesocarp thin and mucilaginous; endocarp ca. 3.7 × 2.2 cm, papyraceous, surface smooth. Seeds with embryo ca. 8 cm long, cotyledons unequal.

Distribution and ecology.

Curarea gentryana is known only from northwestern Ecuador (Fig. 9 ), at elevations of 80-225 m. It is found along creek margins in lowland tropical wet forest. Flowering specimens were collected in April and fruiting specimens were found in February, April and July.

Common names and uses. Ecuador.

“granadilla” (Rubio & Quelal 1434, imm fr).

Eponymy.

The specific epithet honours the late Dr. Alwyn H. Gentry, a dedicated and extraordinary botanist and inspiring mentor, who died tragically in a plane crash in August 1993 while surveying a dry forest reserve in western Ecuador.

Conservation status.

The species is known only from four collections from three localities from northwestern Ecuador. Assessment based on these collections resulted in an Extent of Occurrence (EOO) of 92.6 km2 and an Area of Occupancy (AOO) of 12 km2. The three localities represent three subpopulations, each found in a small communal protected area (Reserva Etnica Awá), the surrounding area of which has been subject to increased land conversion. Therefore, it is expected that the species will in the future be negatively affected by loss of its habitat quality that may lead to reduction in the population and potentially threatening its survival. Thus, C. gentryana is assigned a preliminary status of Endangered [EN, B1ab(i,ii,iii,iv,v) + B2ab(ii,iii,iv,v)].

Discussion.

The velutinous tomentellous indumentum covering the large obovoid or ellipsoid drupelets and the web-like indumentum on the abaxial surface of the broadly ovate leaves are unique to Curarea gentryana . The staminate inflorescences of C. gentryana somewhat resemble those of C. cuatrecasasii . However, C. gentryana has the spatulate inner petals with the lateral margins adaxially connate; spatulate inner petals may also be found in C. cuatrecasasii , but the lateral margins are not adaxially connate.

Paratypes.

ECUADOR. Esmeraldas: San Lorenzo Canton, Reserva Indígena Awá, Parroquia Ricaurte, Centro Guadualito, 01°15'N; 078°40W, 80 m, 20-29 Apr 1992, (fr), Aulestia et al. 9 (MO!, QCNE!); Creek on left side of Rio Palaví, going up river, 2 bends up from Awá encampment past first island, 01°07N; 078°37'W, 225 m, 14 Feb 1988, (imm fr), Hoover et al. 4530 (MO!); Comunidad Balsareño, Río Palabí, 01°09'N; 078°31W, 100 m, 15-29 Apr 1991, (fr), Rubio & Quelal 1434 (MO!, QCNE!).

Figures

Figure 9. Geographic distribution of Curarea barnebyana, C. candicans, C. crassa, C. cuatrecasasii and C. gentryana.

Figure 19. Curarea gentryana staminate plant: A flowering branch B detail of inflorescence C flower bud D inner sepal, adaxial surface E-F outer and inner petals, abaxial and latero-adaxial surfaces G-H outer stamens, abaxial and lateral views I pistillate plant, infructescence (A-H based on Rubio & Quelal 1503 I based on Aulestia et al. 9).