Harpalyce torresii São-Mateus & M. Sousa, 2018

São-Mateus, Wallace M. B., Sousa, Mario, Cardoso, Domingos & Queiroz, Luciano Paganucci De, 2018, Two new Mesoamerican species of Harpalyce (Leguminosae, Papilionoideae), Phytotaxa 344 (2), pp. 160-168 : 161-163

Harpalyce torresii São-Mateus & M. Sousa , sp. nov. ( Figs. 1‒3 )

Harpalyce torresii differs from all other Mesoamerican species mainly by the variegated upper leaflet surface, with bluish patches along the mid and secondary veins or throughout the surface, in addition to the suborbicular vexillum, and wing petals auriculate only on the vexillar side, and with sinuous carinal margin (vs. leaflets with uniform color, vexillum ovate to obovate, wing petals auriculate or sinuous on both margins).

Type: ― BELIZE. Belize: A 15‒20 km al W de Hattieville, camino de Belice a Belmopán, 02 May 1982 (fl), O. Téllez V., T.P. Ramamoorty & M. Panti 5645 (holotype: MEXU!, isotype: MO!).

Shrubs to trees 2‒8 m tall, stems 20‒25 cm dbh, canopy irregular, bark whitish to marbled, scaly; young branches, petiole, leaf rachis, pulvinules, and inflorescence axes pubescent or ferruginous-tomentose to sparsely pubescent when mature, trichomes short and erect; branches cylindrical-angular and with tiny, rounded, cream lenticels. Stipules ca. 0.5 × 0.5 mm, deltate, caducous. Leaves (8‒) 11‒17 cm long, imparipinnate; petiole (2.5‒) 3‒4.5 cm long, slender, glabrescent; rachis (3‒)5‒10.5(‒12) cm long, interfoliolar segments (1.5‒) 2‒3 cm long; leaflets (5‒)7‒11, alternate, subopposite to opposite, dark-green or pale-green, membranaceous when young, subcoriaceous at maturity, brochidodromous, midvein prominent on lower surface, secondary and tertiary veins somewhat inconspicuous and strongly reticulate, secondary veins 11‒13 pairs, discolor, upper surface usually variegated with bluish tones along the midvein, secondary veins or throughout its surface, lower surface pale green when young and dark-green when mature, yellowish, globose peltate glands present only on the lower surface, margins entire and slightly revolute, upper surface glabrous, lower surface puberulent to ferruginous-velutinous, trichomes concentrated along the midvein, pulvinules ca. 5 mm long; lateral leaflets usually slightly larger towards the leaf apex, (3.7‒)4.5‒6(‒7.3) × (1.8‒) 2.1‒3 cm, oval-elliptic to oval-lanceolate, rarely oblong-ovate, base rounded or acute, apex retuse to acute or obtuse, seldom rounded, distal leaflet 4‒6(‒7) × 2‒3 cm, the shape similar to the lateral ones. Inflorescence a panicle ca. 8 cm long or more commonly single racemes 7‒8 cm long, 6‒10-flowered, axillary or terminal, smaller than the subtending leaf; bracts caducous; pedicels 1‒1.5 cm long, tomentose with ferruginous hairs; bracteoles 0.5‒1 × 0.2‒0.5 mm, caducous, attached to the base of the calyx or along the pedicel, triangular to triangular-lanceolate, ferruginous-pubescent; flower bud ca. 2 × 0.6 cm, oblong, apex slightly incurved and acute. Flowers ca. 3.2 cm long, asymmetrical, papilionate, non-resupinate; calyx outer surface sparsely to densely pubescent with ferruginous hairs, short and slightly adpressed, the inner surface glabrous, strongly bilabiate, the vexillar lip 2.3‒2.9 × 0.8‒0.9 cm, broadly ovate, carinal lip 2.9‒3.2 × 0.6‒0.8 cm, oblong-lanceolate; petals membranaceous, glabrous; vexillum 2.9‒3.1 × 2.3‒2.9 cm, pink turning into white when dry, suborbicular, base attenuate, slightly sinuous, apex retuse, claw 2.4‒2.6 cm long; wing petals 2.8‒2.9 × 1.1‒1.3 cm, light-pink, obovate, base retuse, auriculate only at the vexillar side, discreetly sinuous on the carinal margin, the vexillar auricle ca. 4 × 2 mm, apex rounded, claw ca. 2.5 cm long; keel petals 3.1‒3.4 × 0.3‒0.6 cm, light-pink to white, narrowly oblong to oval-oblong and strongly falcate, connate on the base up to the claw, base auriculate on the vexillar margin, the auricle ca. 3 mm long, deltate, apex obtuse, claw ca. 2.9 cm long; stamens 10, 2.2‒2.6 cm long, pseudomonadelphous, fused into a staminal tube deeply divided along the vexillar side, incurved, filaments free at apex for 0.8‒1.1 cm, anthers elliptic-lanceolate, dimorphic, alternately short and long, larger ones 3‒3.5 × 0.6 mm, basifixed, the smaller ones ca. 2 × 0.8 mm, dorsifixed; gynoecium 2.5‒3.5 cm long, ovary 0.8‒1 cm long, sessile, widely-oblong, erect, 6-ovulate, glabrous along the carinal margin and densely pubescent along the vexillar margin, with flexuous, short, golden hairs, carinal margin sparsely pubescent, style 1.7‒2.3 cm long, glabrous except for the margin pilose basally, filiform, curved, stigma capitate, pubescent. Legumes 8.5‒11 × 1.8 cm, elastically dehiscent, compressed, oblong to oblong-obovate, base truncate, slightly cuspidate at apex, the cusp ca. 2 mm long, glabrous, margins straight to slightly sinuous, septa absent, valves coriaceous, brown, rough when young and rough-striate at maturity. Seeds 6, 1‒1.2 × 0.9‒1 cm, compressed, widely-ovate, reddish-brown; strophiole gristly.

Etymology: ―The specific epithet “ torresii ” honors Rafael Torres, a Mexican botanist at Universidad Nacional Autónoma de México (UNAM), who has enormously contributed to the floristic knowledge in the state of Oaxaca.

Distribution and habitat: ― Harpalyce torresii occurs in Belize and Mexico. This new species is found in seasonally dry tropical forest and woodlands (“selva baja caducifolia” and “selva baja subperenifolia”) and less frequently in secondary forests. Such vegetation formations are characterized by tree canopy up to 15 m high, periodic flooding, with flat, deep, clay-rich soils with deficient drainage, where the caesalpinioid legume Haematoxylum campechianum Linnaeus (1753: 384) generally predominates, forming dense groups locally known as “tintales” ( Pennington & Sarukhán 2005).

Phenology: ―The species was found flowering in June. Fruiting specimens were seen from September to April”.

Conservation status: ―The new species Harpalyce torresii can be considered Endangered [EN, B2a,b(i,ii,iii)] according to IUCN’s (2012) categories and criteria, and the extent of occurrence of 13,173 km 2 and area of occupancy of 16 km 2, as assessed through GeoCAT ( Bachman et al. 2011). Moreover, H. torresii occurs only in four localities in Belize and Mexico.

Additional specimens examined (paratypes): ― BELIZE. Belize: A 18 km al SW de Hattieville, en Western Higway , 10 December 1981 (fr), M. Sousa et al. 12132 (MEXU) . Cayo District: 200 yards S of Blue Hole on Hummingbird Highway 28 May 1971 (fr), J. Utley 794 (F) . MEXICO. Campeche: Calakmul : 2.9 km al NE de Pioneros del Río, 17º54’14”N, 89º09’06”W, 30 m, 17 February 2002 (fr), J.C. Soto et al. 21547 (MEXU) . Tabasco: Balacán: A 20 km, hacia El Triunfo , Tab. Crucero Balacán , El Triunfo , 23 September 1979 (fr), O. Téllez & E. Martínez 950 (MEXU) ; Villa El Triunfo, El Diamante , 15 April 1995 (fl), L. Castillo & F. Javier s.n. (MEXU 1178804, 1186534) .

Discussion: ― Harpalyce torresii can be distinguished from all other Mesoamerican species of the genus mainly for presenting variegated upper leaflet surface with bluish patches along the mid and secondary veins or throughout the upper surface. This new species is morphologically similar to the herein described H. yucatanense , both presenting large flowers with pink petals that turn white when dry, and the oblong-obovate fruits of similar size. However, H. torresii is differentiated by the pubescent calyx (vs. tomentose), the vexillar lip broadly ovate (vs. oblong-elliptic), suborbicular vexillum lacking basal auricles and retuse at the apex (vs. widely ovate, with basal and inflexed auricles, apex rounded), and obovate wing petals that are auriculate only on the vexillar margin, the carinal margin sinuous (vs. oblong-obovate and auriculate on both margins).

Figures

FIGURE 1. Harpalyce torresii. A. Fruiting branch. B. Detail of the variegated upper surface. C. Inflorescence. D. Floral bud. E. Vexillar lip. F.Carinal lip. G. Vexillum. H. Wing petal. I. Keel petal. J. Closed staminal tube. K. Open staminal tube. L. Gynoecium. M. Seed. (A. From M. Sousa et al. 12132, MEXU; B‒M. From O. Téllez V. et al. 5645, MEXU). Drawn by Ramiro Cruz.

FIGURE 2. Harpalyce yucatanense. A. Flowering and fruiting branch. B. Floral bud. C. Bracteole. D. Vexillum. E. Wing petal. F. Keel petal. G. Closed staminal tube. H. Open staminal tube. I. Gynoecium in the center of the calyx. J. Detail of ovary and style. (A. From O.G. Enriquez 582, MEXU; B‒J. From E. Cabrera & H. de Cabrera 8687, MEXU). Drawn by Ramiro Cruz.

FIGURE 3. Distribution range of the two species of Harpalyce described here: ▲ H. torresii (Belize and Mexico) and ● H. yucatanense (Mexico).