Eriosema parvifolium Pavan & Fort.-Perez

Campos, Renan Pavan, Cândido, Elisa Silva, Zeferino, Laís Couto & Fortuna-Perez, Ana Paula, 2023, A New Species of Eriosema (Leguminosae, Papilionoideae, Phaseoleae) from the savannas of northern South America, Phytotaxa 612 (3), pp. 293-300 : 294-295

Eriosema parvifolium Pavan & Fort.-Perez , sp. nov. (Fig. 1,3)

Diagnostic Characters: Eriosema parvifolium is characterized by short habit (0.1–0.3 m tall), stipules 0.3–0.7 cm long, and leaflets discolored, narrow elliptical. E. parvifolium differs from E. crinitum var. crinitum by the diameter of its stipules that is 3–7 mm (versus 7–17 mm), size of leaflets (including terminal and lateral) that is 1–3.5 x 0.25–0.5 cm (versus 5–12 x 0.5–1.2 cm), and calyx lobes 2–3 mm (versus 2.5–5.5 mm), differs from E. crinitum var. stipulare by leaves with narrow elliptical leaflets and yellow pubescent indumentum (versus leaves with a densely whitish pubescent and puberulent indumentum), Eriosema parvifolium differs from E. violaceum by having pauciflorous racemes (versus spiciform inflorescence and multiflora).

Type:— BRAZIL. Roraima: Caracaraí. Vista Alegre , 1º42’16’’N, 61º08’43’’ W, elev. 67 m, 11 February 2016, fl., H. C. de Lima et al. 8134 (holotype RB [barcode] 01096592 !) .

Subshrub ca. 0.1–0.3 m tall, stems erect, yellow hirsute pilose. Stipules connate, 3–7 × 1.5–2 mm, lanceolate, apex acute, persistent, externally pilose. Stipels absent. Leaves trifoliolate, subsessile petioles 0.5–1 mm long. Lateral leaflets 1–2.5 × 0.25–0.5 cm, terminal leaflets 2–3.5 × 0.35–0.5 cm, without clearly marked veins, adaxial and abaxial surfaces yellowish pubescent or whitish yellow pubescent, narrowly elliptic, apex mucronate, margins entire, discolored, slightly revolute, petiolule up to 1 mm long, pilose. Bracts 2–2.5 × 1–1.5 mm, ovate to lanceolate, adaxial surface densely pilose, abaxial surface glabrous, multi-veined. Racemes axillary, up to 2–5 flowers, 0.5–1.6 cm long (peduncle + rachis), pilose, pedicels 2.5–4 mm long, flowers 8.5–10 mm. Calyx 5-lobed, pilose, margins entire, 5- veined; tube 1.5–2 mm long, two vexillary lobes 2–2.5 mm long, three carenal lobes 2.5–3 mm long. Corolla yellow, standard 6.5–8 × 4–6 mm (excluding claw), obovate, multi-veined, apex slightly retuse or slightly emarginate, base auriculate, auricles 0.5 mm long, adaxial surface pubescent, abaxial surface glabrous; claw 1–1.5 mm; wing petals 6–6.5 × 1.5–2.5 mm (excluding claw), obovate, apex rounded, glabrous, slightly auriculate, auricles 0.5 mm long; claw 2–2.5 mm long; keel petals 4.5–5 × 1.5–2.5 mm (excluding claw), falcate to obovate, apex rounded, glabrous to pilose at the apex; claw 2.5–3 mm long. Stamens 8.5–9 mm long, uniform. Ovary densely sericeous, style straight, stigma minute. Fruit not seen.

Additional Specimens Examined (Paratype):— VENEZUELA. Bolívar: Cedeño, Las Bonitas, Boca de Tucuragua , 7º48’N, 65º18’W, elev. 50 m, February 1988 (fl.), J. Velazco 114 ( US [barcode] US-815264 ) ; Celedonia, em la sabana de Maripa , Bajo Caura , elev. 100m, 21 April 1939 (fl.fr.), L. Willians 11935 ( M [barcode] M-871195 image!) .

Distribution and habitat:— Eriosema parvifolium is known only from the holotype and paratypes locality ( Fig. 2 ) where it grows in savannah areas of Bolívar-Venezuela and Roraima-Brazil.

Phenology: —The species was collected with flowers in February and April.

Etymology:—The specific epithet parvifolium derives from the combination of parvum + folium, due to the leaves of reduced proportions in relation to other species of the genus.

Conservation Status:—According to the IUCN Red List criteria ( IUCN 2019), the conservation status of Eriosema parvifolium must be considered Data Deficient (DD), because it is represented by only three collections, one without location.

Taxonomic Comments:— Eriosema parvifolium resembles E. crinitum (Kunth) G.Don var. crinitum , E. crinitum var. stipulare (Benth.) Fortunato , and E. violaceum (Aubl.) G.Don. in having conate and lanceolate stipules and narrow elliptical leaflets ( Fig. 3A–F ). Eriosema parvifolium differs from E. crinitum var. crinitum by the diameter of its stipules that is 3–7 mm (versus 7–17 mm), size of leaflets that is 1–3.5 x 0.25–0.5 cm (versus 5–12 x 0.5–1.2 cm), and leaflets pilose, ca. 1 mm long (versus pilose to puberulous, 1–3 mm long; Fig. 3A–B ). Differs of Eriosema crinitum var. stipulare by having yellow pubescent indumentum and leaves with narrow elliptical leaflets (versus leaves with a densely whitish pubescent and puberulent indumentum and linear, lanceolate to narrow elliptical leaflets; Fig. 3C–F ). Eriosema parvifolium differs from E. violaceum by having pauciflorous racemes, with length equal to or less than the leaves (versus spiciform inflorescence and multiflora, generally larger than the mature leaves).

Figures

FIGURE 2. Distribution map of Eriosema parvifolium. The new species has been recorded from the state of Bolívar- Venezuela and Roraima- Brazil.

FIGURE 3. Leaflet indumentum of Eriosema parvifolium and morphologically most similar taxa. Eriosema crinitum var. crinitum: A) Indumentum on the adaxial surface. B) Indumentum of the abaxial surface. Eriosema crinitum var. stipulare: C) Indumentum of the adaxial surface. D) Indumentum of the abaxial surface. Eriosema parvifolium: E) Indumentum of the adaxial surface. F) Indumentum of the abaxial surface. Photos by Renan Pavan.