Eriosema magnum Fort.-Perez, Pavan & M.J.Silva sp. nov. (Fig. 1)

Diagnostic Characters: Eriosema magnum characterized by long habit (1.3–1.8 m tall), venation brochidodromous of leaves, petioles 4.5–5 mm long, flowers throughout the inflorescence (raceme), pedicels 6–8 mm long, and indumentum yellow-hirsute. Similar taxa, E. rufum var. rufum and E. rufum var. macrostachyum, present the size of plants to 1 meter long, venation camptodromous of leaves, petioles 1–4 mm long, flowers in apex of inflorescence like a glomerulum, pedicels 2–5 mm long, and indumentum rufous-pilose.

Type:— BRAZIL. BRASIL. Goiás: Niquelândia, Reserva Particular de Desenvolvimento Sustentável Legado Verdes do Cerrado, Núcleo Engenho, Área do Coimbra, morro após a Caverna, margem de Cerradão, 14°34’40”S, 48°31’51”W, 588 m. a.s.l., 27 Mar 2021 (fl., fr.), M. J. Silva & I. S. Santos, 12174 (holotype BOTU 38583!; isotype BOTU 38584!) .

Subshrub 1.3(–0.8)– 1.8 m tall, erect, adult stems brownish or blackish, yellowish hirsute trichomes. Stipules usually free, 6.5–10 × 3.5–4.7 mm, ovate or ovate-lanceolate, apex cuneate, persistent, externally pilose. Stipels absent. Leaves trifoliolate, petioles 4.5–5 mm long; lateral leaflets 0.4–7.5 × 1.8–3.4 cm, terminal leaflets 4.5–9 × 1.6–4 cm, both ovate, ovate-elliptical, and oblong-elliptical, base obtuse, margin entire, apex acute and shortly mucronate, conspicuously pubescent yellowish on both surface; discolored adaxial surface light green, abaxial surface opaque green; petiolule up to 1 mm long, pilose; venation brochidodromous, primary and secondary veins clearly marked on adaxial surface and prominent on abaxial surface. Bracts 4–6.5 mm long, ovate, lanceolate or combinations, external surface densely pilose; inner surface glabrous, multi–veined. Racemes axillary, multiflorous, 5–17 flowers, 3–5 cm long (peduncle + rachis), pilose, congested; flowers 8–13 mm, pedicels 6–8 mm long. Calyx 5– lobed, pilose, margins entire; tube 1.8–2 mm long, two vexillary lobes 2–4 mm long, three carenal lobes 2.5–4.8 mm long. Corolla yellow, standard 8–9.5 × 6–6.7 mm (excluding claw), obovate, multi–veined, apex slightly retuse or slightly emarginate, base auriculate, auricles 1–1.3 mm long, external surface pubescent, inner surface glabrous; claw 2–2.6 mm; wing petals 7–7.5 × 2–2.5 mm (excluding claw), obovate, apex rounded, glabrous, slightly auriculate, auricles 0.3–0.6 mm long, claw 2.8–3 mm long; keel petals 6–7 × 3–3.5 mm (excluding claw), falcate-obovate, apex rounded, glabrous to pilose at the apex, claw 3.4–3.5 mm long, auricles 0.2 mm long. Stamens 9.5–10.5 mm long, uniform, anthers 0.3 mm long. Ovary pilose, 3.5–4 mm long, style straight, stigma minute. Fruit legume, 15–15.5 × 9–10 mm, oblong, pilose.

Additional Specimens Examined (Paratypes): — BRASIL. Goiás: Niquelândia, Reserva Particular de Desenvolvimento Sustentável Legado Verdes do Cerrado, Núcleo Engenho, área da Filipa cerca de 200 metros da estrada que leva ao Zé Gordo, lado direito, Cerrado Denso, 14°35’03”S, 48°24’43”W, 697 m. a.s.l., 20 Feb 2021 (fl., fr.), M. J. Silva & I. S. Santos 11975 (BOTU 38585), 11976 (BOTU 11976); ibd., Área do Zé Gordo, cerca de 100 metros a partir da entrada que leva a casa abandonada do Zé Gordo, cerrado típico, 14°34’32”S, 48°23’39”W, 642 m. a.s.l., 20 Feb 2021 (fl., fr.), M. J. Silva & I. S. Santos 11992 (BOTU 38587) ; Área do Coimbra, morro após a Caverna, margem de Cerradão, 14°34’40”S, 48°31’51”W, 588 m. a.s.l., 27 Mar 2021 (fl., fr.), M. J. Silva & I. S. Santos 12171 (BOTU 38588) .

Distribution and habitat: — Eriosema magnum is known only from the holotype, isotype and paratypes locality (Fig. 2) where it grows in typical cerrado and “cerradão” in clay and sandy clay soils between 588 and 697 meters elevation.

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

Etymology: —The specific epithet magnum is because of the imposing size of the plant.

Preliminary Conservation status: — Eriosema magnum must be considered Endangered (NE), with an extension of occurrence of 11,336 km ² and an Area of Occupation of 12,000 km ², based on the width from the cell (2 km). Currently, the species has four recent records, this one occurring in environmentally protected areas.

Taxonomic Comments: — Eriosema magnum shares with E. rufum (Kunth 1823: 423) G. Don (1832: 347) var. rufum and E. rufum var. macrostachyum (DC. 1825: 388) G. Don (1832: 347) the erect habit of the plant, stems and leaves densely hirsute, leaves with primary and secondary veins clearly marked on the adaxial surface and prominent on the abaxial surface. However, it is differentiated from other taxa by the characters listed in the table below (Table 1).

Key to the species of Eriosema of the Legado Verdes do Cerrado region, Niquelândia, Goiás

1. Plants with deciduous leaves when fertile..................................................................................................................... E. congestum

- Plants with persistent leaves when fertile...........................................................................................................................................2

2. Stems glabrous or glabrescent; leaflets clearly with three veins evident .......................................................................... E. glabrum

- Stems pubescent; leaflets without three veins evident .......................................................................................................................3

3. Leaflets usually more than five times longer than wide.....................................................................................................................4

- Leaflets usually less than five times longer than wide.......................................................................................................................6

4. Racemes with 2–5 flowers................................................................................................................................................. E. crinitum

- Racemes with more than 8 flowers ....................................................................................................................................................5

5. Stems densely whitish pubescent ...................................................................................................................................... E. strictum

- Stems glabrescent, yellowish or rufous pubescent ....................................................................................................... E. longifolium

6. Stipules 17–25 mm long...................................................................................................................................... E. macrostipulatum

- Stipules less than 11 mm long ............................................................................................................................................................7

7. Flowers throughout the inflorescence (raceme), inflorescence with trichomes hirsute-yellowish .................................. E. magnum

- Flowers in apex of inflorescence like a glomerulum, inflorescence with trichomes rufous-pilose ...................................... E. rufum