Eremanthus tomentosus Loeuille & Bringel, 2022

Loeuille, Benoît, Bringel Jr, João Bernardo De A., Faria Jr, Jair E. Q. & Valls, José F. M., 2022, Three new species of Lychnophorinae from the Brazilian Central Plateau (Asteraceae: Vernonieae), Phytotaxa 531 (3), pp. 249-266 : 250-253

Eremanthus tomentosus Loeuille & Bringel , sp. nov. ( Fig. 1 , 2 )

Species Eremantho cincto caulibus rufo-brunneo tomentosis, syncephaliis hemisphaericis, bracteis secundariis conspicuis similis, sed foliis petiolatis (non sessilibus), supra tomentosis (non glabratis), capitulis per 3/4 longitudinem connatis (non per totam longitudinem) et cypselis rubro-glanduliferis basi differt.

Type: — BRAZIL. Minas Gerais: Paracatu, seguindo pela GO-020 atravessando o rio São Marcos e adentrando no estado de Minas Gerais, ca. 38 km L da BR-050, 17°22’39”S, 47°28’59”W, elev. 917 m, 07 June 2020, J . B . A. Bringel & J . E . Q. Faria 1713 (holotype CEN!; isotypes UFP!, RB!, MBM!) .

Description: —Treelet up to 1.5 m. Stems moderately branched, reddish-brown tomentose with semicircular leaf scars following leaf fall,younger branches furrowed.Leaves alternate, simple;petiole 0.5–1.2cm long, upper leaves subsessile, base enlarged; blade oblong or elliptic, sometimes narrow obovate, 5.7–10.1 × 2.4–3.6 cm, venation brochidodromous, midrib and secondary veins prominent abaxially, midrib furrowed, adaxial surface willow green, tomentose, abaxial surface green-greyish, sometimes slightly reddish-brown, densely tomentose, tomentum of unbranched, long, thin trichomes, 3- to 5-armed, bladder-like trichomes and 3- to 5-armed not swollen trichomes, coriaceous, margins entire, flat, apex obtuse or slightly acute, base acute, sometimes obtuse. Capitula fused in a syncephalium (secondary order inflorescence), sometimes 2–5 syncephalia juxtaposed into a tertiary order inflorescence, organized in a terminal cyme (not compound) of 3–7 syncephalia. Syncephalium 1.1–2.4 cm tall, 1.3–2.4 cm diam., hemispherical; secondary bracts ovate, base obtuse, leaf-like, 0.5–2 × 0.3–0.9 cm long. Capitula 20–ca. 100, homogamous, discoid, sessile, fused 3/4 of length; involucre 3.2–5.3 mm tall, 1.7–3 mm diam., obconic, 4–5-seriate, subequal; phyllaries weakly imbricate, narrow elliptic or narrow oblanceolate, light greenish, upper half darker, apex obtuse, densely lanulose, margins scarious, persistent, outer phyllaries 2.5–3 × 0.3–0.4 mm, inner phyllaries 3.5–4.6 × 0.4–0.6 mm long; receptacle flat, naked. Florets 1 per capitulum, bisexual, fertile; corolla actinomorphic, deeply 5-lobed, lilac, corolla tube 2.5–3.2 × 0.5–0.8 mm, villose towards base, corolla lobes 3–3.2 × 0.5–0.6 mm, glandular-punctate, pilose towards apices, apex acute; anther whitish or lilac, apical anther appendages lanceolate, acute, anther base sagittate, acute; style shaft 4.5–5.5 mm long, white or pale lilac, glabrous throughout except for pubescent upper ca. 1 mm beneath style arms, style arms 1–2 mm long, apex acute, pubescent outside, hairs acute, style base glabrous, lacking basal node. Cypsela turbinate, 2.9–3.1 × 0.8–1 mm, obscurely-ribbed, light brown, sericeous, densely reddish glandular-punctate at base (when fully developed); carpopodium inconspicuous; pappus setae 3–4-seriate, stramineous, paleaceous, persistent, ± serrulate, outermost series setae 1–2.1 mm, innermost series setae 4–5.1 mm.

Distribution, habitat, and conservation status: — Eremanthus tomentosus grows in hillsides in campo sujo (open grassland with few, scattered shrubs or treelets) on cambisol with small quartzitic rocks. It is currently known from three populations in southeastern Goiás and surrounding areas in Minas Gerais, near the São Marcos river. In addition, a fourth population was found about 160 km away, in the Brasília Botanical Garden reserve in the Distrito Federal ( Fig. 3 ). According to the IUCN (2019) criterion of geographic range, this species is recognized as Endangered, since its extent of occurrence is estimated in 2,327 km 2 and area of occupancy in 16 km 2.

Etymology: —The species epithet refers to the tomentose indument covering the adaxial leaf surface of the new species.

Additional specimens examined (paratypes):— BRAZIL. Distrito Federal. Brasília. Estação Ecológica Jardim Botânico de Brasília, área do Morro do Urubu , 15°54’58”S, 47°53’28”W, elev. 1125m. J . E .Q. Faria 10684 ( HEPH, UB, UFP) . Goiás. Campo Alegre de Goiás, estrada à direita da GO-213 ca. 21 km NE de Campo Alegre , 17°32’31”S, 47°39’22”W, elev. 917 m, 06 June 2020, J . B .A. Bringel Jr. & J . E .Q. Faria 1700 ( CEN, UFP); margem da GO-213, ca. 13 km de Campo Alegre – GO , 17°32’55”S, 47°42’00”W, 06 June 2020, J . B .A. Bringel Jr. & J . E .Q. Faria 1684 ( CEN, UFP); ibid., J . E .Q. Faria & J . B .A. Bringel Jr. 10651 ( HDJF, HUEG, RB, UB, UFP); rodovia não pavimentada GO-213, ca. 13.5 km E do entroncamento com a BR-050, 17°32’54”S, 47°42’01”W, 29 July 2018, J . B .A. Bringel Jr. & J . E .Q. Faria 1368 ( CEN, UFP) . Minas Gerais. Paracatu, seguindo pela GO-020 atravessando o rio São Marcos e adentrando no estado de Minas Gerais, ca. de 38 km E da BR-050, 17°22’39”S, 47°28’59”W, elev. 886 m, 07 June 2020, J . E .Q. Faria & J . B .A. Bringel Jr. 10679 ( HDJF, HEPH, RB, UB, UFP) .

Discussion: — Eremanthus tomentosus belongs to E. subgen. Eremanthus sect. Synglomerus MacLeish (1987: 275) because of the heads organized in a cyme of syncephalia (not a compound cyme of syncephalia like in sect. Eremanthus ), obconic heads and cypsela with a paleaceous, persistent pappus ( MacLeish 1987). It is morphologically related to E. cinctus Baker (1873: 162) by its reddish-brown tomentose stems and hemispherical syncephalium surrounded by conspicuous secondary bracts. However, the new species differs from E. cinctus by its petiolate leaves (vs. sessile), the adaxial leaf surface tomentum (tomentose vs. glabrate), secondary bracts with constricted obtuse bases (vs. prominently enlarged bases), heads fused in 3/4 of length (vs. fused in the entire length) and cypsela with reddish glands at the base (vs. without reddish glands at the base). The other Eremanthus species with adaxially tomentose leaves is E. mollis Schultz-Bipontinus (1861: 166) , which also shares with E. tomentosus the presence of third order syncephalia in some individuals. The new species differs by its habit (treelet vs. subshrub to shrub), inflorescence type (cyme of syncephalia vs. corymb of syncephalia), syncephalium shape (hemispherical vs. spherical), number of pappus series (3–4-seriate vs. biseriate). Eremanthus tomentosus occurs in sympatry with four other species of the genus: E. mollis , E. glomerulatus Lessing (1829: 317) , E. goyazensis ( Gardner 1847: 425) Schultz-Bipontinus (1861: 165) , and E. mattogrossensis Kuntze (1898: 145) , but these species have compound cymes of syncephalia with heads fused in less than 1/2 of the length ( E. glomerulatus and E. mattogrossensis ) or the entire length ( E. goyazensis ) (vs. not compound cyme and heads fused in 3/4 of the length) ( MacLeish 1984, 1987, Loeuille et al. 2019) ( Table 1 ). A hybrid origin of the new species cannot be excluded since E. goyazensis and E. mollis share some morphological traits with the new species and the three of them were always found sympatrically. Nonetheless, only E. tomentosus displays corolla villose towards the base and cypsela with reddish glands at the base. We encourage future efforts to investigate this hypothesis.

Figures

FIGURE 1. Eremanthus tomentosus. A. Flowering branch. B. Leaf adaxial surface. C. Leaf abaxial surface. D. Cyme of syncephalia. E. Tertiary order inflorescence. F. Longitudinal section of syncephalium. G. Corolla, androecium and upper part of style. H. Cypsela with pappus. A.–I. from Bringel Jr. & Faria 1713 (UFP).

FIGURE 2. Eremanthus tomentosus. A. Habitat. B. Habit. C. Stem. D. Leaf abaxial surface. E. Cyme of syncephalia. F. Tertiary order inflorescence. G. Fruiting syncephalium. A.–E., G. by J.E.Q. Faria. F. by J.B. Bringel Jr.

FIGURE 3. Distribution of the three new species of Lychnophorinae (Vernonieae – Asteraceae).