Mimosa crassifolia J. Gelma, L.P. Queiroz & Van den Berg, 2023

Do Nascimento, Janaína Gelma A., Rocha, Lamarck, Dutra, Valquíria F., De Queiroz, Luciano P. & Berg, Cássio Van Den, 2023, Four new species of Mimosa sect. Batocaulon ser. Cordistipulae (Leguminosae) from Bahia, Brazil, Phytotaxa 599 (5), pp. 265-279 : 271-273

3. Mimosa crassifolia J. Gelma, L.P. Queiroz & Van den Berg , sp. nov. Figs. 3A–G , 5 .

Type — BRAZIL. Bahia: Município de Morro do Chapéu, Tabuleiro dos Tigres, Morro do Chapéu , 20 July 2005 (fl., fr.), A.K.A. Santos 355 (holotype: HUEFS [barcode 000001300]!; isotype: HUEFS [barcode 000001255]!) .

Affinis M. morroënsi Barneby (1985: 147) sed petiolo breviore ((5–) 8–15 mm longo (nec 20–30 mm longo)), foliolis coriaceis nitidis glabris (nec membranaceis opacisque, sericeis vel ciliatis), trichomatibus glandularibus conicis 0.05– 0.3 mm longis (nec trichomatibus glandularibus linearibus 0.5–0.8 mm longis) differt.

Decumbent subshrub 0.3–0.5 m tall, rarely erect; branches cylindrical, puberulous, with filiform trichomes, and capitate-filiform glandular trichomes, 0.05–0.3 mm long. Internodes 18–20 mm long. Stipules 3–7 × 0.8–1.2 mm, lanceolate, base truncate, apex acuminate, aristate, margin ciliate, 3-veined. Petiole (5–) 8–15 mm long, rachis 23–70 mm long, first interpinnal segment 4–8 mm long, remaining segments 3–5 mm long; pinnae 9–14(–18) pairs, slightly decreasing in size toward to the apex and the leaf base, median pinna 15–20 mm long; leaflets 9–15 pairs per pinna (median pinnae), coriaceous, glossy, 2–4 × 0.8–1.8 mm, oblong, apex obtuse, base rounded, both surfaces glabrous, 3-veined, margins with capitate-setiform trichomes. Capitula 10–15 mm diam., 45–60-flowered; peduncle 33–49 mm long; bracts 0.4–1.3 × 0.1–0.25 mm, membranaceous, linear or spatulate. Flowers sessile; calyx white, 0.4–0.8 mm long, campanulate, slightly asymmetric, lobes with apex acute, slightly dentate; corolla white with a pink rim, glabrous, subtubular, membranaceous, tube 0.4–1.4 mm long, lobes 0.8–2.5 mm long, acuminate; stamens 6, filaments connate ca. 0.5 mm long at the base, three longer 6–8 mm long, three shorter 4–6 mm long, dark-pink; anthers 0.6–0.7 mm long, globose, yellow; ovary ca. 1 mm long, with filiform and capitate-filiform glandular trichomes, stipitate, stipe ca. 0.5 mm long, 4-ovulate; style 3–5.5 mm long. Craspedium 20–25 × 5–7 mm, subsessile, straight oblong, margin undulate, puberulous, with filiform and capitate-filiform trichomes, 2–3-articulate, apical and basal articles triangular, median articles rectangular, 5–6 × 4–5 mm. Seeds 3–4 × 2.8–3 mm, external surface smooth.

Distribution, habitat and phenology: — Mimosa crassifolia is known only from the Morro do Chapéu municipality, northern Chapada Diamantina range, Bahia, Brazil ( Figure 5 ). The specimens were collected in sandy areas of the campo rupestre, at 1,000 –1,100 m of elevation, with flowers from January to July, and fruits in January to May.

Conservation:— We propose this species to be endangered (EN, criteria B2ab(iii)+D). Mimosa crassifolia is known from only a few collections made in the municipality of Morro do Chapéu (EOO 5,302 km 2 and AOO 8,000 km 2), in “Tabuleiro dos Tigres”, a specific area of campos rupestres, and at Morro do Chapéu State Park. The municipality of Morro do Chapéu is located at the northern portion of Chapada Diamantina and is considered an area of extreme priority for conservation, as it has a plant typology of savannas and caatinga ( Maury 2002, França et al. 2013). One of the populations of Mimosa crassifolia was found in the Morro do Chapéu State Park, which despite being an protection area, continues to suffer anthropic pressures, such as fragmentation due to subsistence agriculture (Lob„o & Vale 2009), which puts the presence of the species in risk.

Etymology: — The specific epithet crassifolia refers to the fleshy consistency of the leaflets when fresh.

Notes:— The multipopulational morphological study in the Mimosa misera complex, using multivariate analysis, pointed out that specimens found in herbaria and of uncertain identification, represent a new species, M. crassifolia ( Nascimento 2007) . This species is morphologically similar to M. morroënsis , due to its decumbent habit and multipinnate leaves, and they occur in sympatry in the Morro do Chapéu municipality. Mimosa crassifolia can be further recognized by the indumentum composed of very short and conical glandular trichomes (c. 0.05 mm long), while M. morroënsis has slender stipitate glandular trichomes, with 0.5–1.5 mm long. Mimosa crassifolia can still be distinguished by longer internodes (18–20 mm long), larger stipules (3–7 mm long), lanceolate and pungent, smaller petioles, (5–) 8–15 mm long, and leaflets bright, coriaceous, and glabrous, in 9–15 pairs. M. morroënsis , on the other hand, has internodes 25–40 mm long, stipules 0.4–0.6 mm long, petioles 20–30 mm long, and dull, membranous and sericeous leaflets, in 15–18 pairs. Based on reproductive characters, they are distinguished by smaller capitula and sessile flowers, in M. crassifolia (10–15 mm diam. vs. 25–30 mm diam., and pedicellate flowers), and 2–3-articulate craspedium, while M. morroënsis has 4–8-articulate ( Table 3).

Paratypes:— BRAZIL. Bahia: Morro do Chapéu, Morro Duas Irm „s, 2 May 1999 (fl., fr.), F. França et al. 2853 ( CEPEC, HUEFS, SPF) ; ibd., 11°33’39’’S, 41°17’00’’W, 21 July 2005 (fl.), A.K.A. Santos et al. 365 ( HUEFS, SPF) ; ibd., Tabuleiro dos Tigres , 11°36’47’’S, 41°09’46’’W, 4 January 2005 (fl.), J.G.A. Nascimento & M.C. Machado 145 ( HUEFS) ; ibd., Tabuleiro dos Tigres, ca. de 5 km de Morro do Chapéu, estrada para Utinga , 11°36’37’’S, 41°09’46’’W, 4 January 2005 (fl., fr.), J.G.A. Nascimento & M.C. Machado 165 (K, HUEFS, MBM, RB, SPF) .

Figures

FIGURE 3. Mimosa crassifolia. A. flowering branch. B. portion of the branch showing stipules. C. detail of the branch indument, showing glandular trichomes. D. pinnae in adaxial surface. E–F. leaflets showing adaxial (E) and abaxial (F) surfaces. G. flower (Drawing from Santos 355, holotype—HUEFS, by Carla Lima).

FIGURE 5. Distribution map of new species of Mimosa ser. Cordistipulae from Bahia.