Chrysolaena glandulosa P.N. Soares & J.N. Nakaj., 2020

Soares, Polyana Noronha, Gonçalves-Esteves, Vânia, Semir, João & Nakajima, Jimi Naoki, 2020, Chrysolaena glandulosa (Vernonieae, Asteraceae): A new species from Brazil, Phytotaxa 439 (3), pp. 295-300 : 296

Chrysolaena glandulosa P.N. Soares & J.N. Nakaj. , sp. nov. ( Fig. 1 )

Type:— BRAZIL. Minas Gerais: São Roque de Minas, Parque Nacional da Serra da Canastra , 4 km após a entrada para a Cachoeira da Casca D’Anta , 9 December 1994, J. N. Nakajima & R. Romero 707 (holotype HUFU!; isotypes: DIA!, MBM!, SPF!, UEC!, US!) .

Diagnosis:— Herba perennis 0.25–0.5 m alta, basi ramosa, erecta. Folia alterna, laxa, subtus conspicue glanduloso-punctata. Flores ca. 34–37 in capitulis 5–6, lobis papillosis, glanduloso-punctatis; antherae appendice glanduloso-punctatae; achaenia 5-costata, strigosa, glanduloso-punctata.

Perennial herbs 0.25–0.5 m tall, branched at base; stem cylindrical, furrowed, indumentum silvery sericeous. Leaves alternate, laxly disposed, sessile, membranous. Leaf blades 0.9–8.3 × 0.2–2.2 cm, basal elliptic, others oblong-lanceolate to linear-lanceolate, basally attenuate, margin entire to dentate, revolute, apex acute to acuminate, surface strigose, lower surface densely strigose with numerous glandular dots, tomentose mainly on veins, penninervate. Inflorescence terminal with cymose branches, densely sericeous, bracts linear, densely sericeous-strigose. Heads condensed, with ca. 5–6 heads, peduncles 2–13 mm long, densely sericeous-strigose. Involucre campanulate, 19–23 mm high, 3-seriate, purple at apex, sericeous-strigose, outer phyllaries 11–7 × 2– 1 mm, ovate-lanceolate, apically acute to acuminate, inner phyllaries 7–6 × 2– 1 mm, lanceolate. Florets 34–37 per head, corolla 7–10 mm long, lobes 2–2.5 mm long, lanceolate, papillose, with glandular dots. Anthers with apical appendage lanceolate, glandular-dotted, basally calcarate, obtuse, collar slightly prominent. Style 6.5–7.5 mm long, non-sclerified. Cypselae 3–5 mm long, 5-costate, setose-strigose, with glandular dots, raphids elongated, carpopodium symmetric, annular, glabrous. Pappus white, 2-seriate, inner bristles 3–6 mm long, outer scales 1 mm. Pollen grains 45.6 × 51.6 μm, tricolporate, equinolophate, type “C” with 29 lacunae (3 poral, 6 abporal, 12 paraporal, 6 interpolar and 2 polar) and lacking equatorial lacunae, tricolporate and sexine equinolophate.

Specimens examined:— BRAZIL. Minas Gerais: Poços de Caldas , Fazenda Chiqueirão, 3 October 1981, H. F. Leitão et al. s. n. ( UEC!) ; Mun. São Roque de Minas, Parque Nacional da Serra da Canastra , 16 September 1994, R. Romero et al. 895 ( HUFU!) ; guarita de Sacramento, próximo à captação de água, 19 November 1996, R. Romero et al. 3737 ( HUFU!) ; estrada para a Serra da Chapada , 14 October 1997, R. Romero et al. 4577 ( HUFU!) .

Distribution and Habitat:— Chrysolaena glandulosa was collected in “campo limpo” and “campo rupestre”, two distinct phytophysionomies of Brazilian Cerrado Biome. It is restricted to Poços de Caldas and São Roque de Minas municipalities in southwestern Minas Gerais, Brazil ( Fig. 2 ). Furthermore, there are few individuals in each population. This area is situated in the Serra da Canastra National Park, which is known for its high Asteraceae diversity and endemism ( Nakajima & Semir 2001).

Phenology: —Flowering from September to December and fruiting in November and December.

Etymology: —The epithet of this species refers to the presence of numerous glandular dots on leaves, corolla, anther appendages and cypsela.

Taxonomic note:— The new species was included in Chrysolaena since it has sericeous pubescence, seriate-cymose inflorescences, anther appendages with glandular dots, non-sclerified style bases, and pollen of type C ( Fig. 3 ). This pollen type was also found in the species of Stenocephalum Sch. Bip. ( Via do Pico & Dematteis 2013, Mendonça et al. 2007). However, when associated with morphological characters such as number of flowers and shape of heads, it is only possible to include the new species in the genus Chrysolaena , since Stenocephalum is characterized by cylindrical heads with 4–10 flowers ( Robinson 1987, 1999).

Chrysolaena glandulosa is a perennial herb with basal leaves elliptic, other leaves oblong-lanceolate to linear-lanceolate with glandular dots on the lower surface, 5–6 heads with 34–37 flowers, lobes with papillose apex and glandular dots. The new taxon is similar to C. campestris (DC.) M. Dematt. , but the latter species has glabrous corolla and inflorescence with only 2–3 heads, with 25–30 flowers per head.

Figures

FIGURE 1. Chrysolaena glandulosa. A. Habit and detail of leaves indumentum. B. Head. C. Floret and lobe apex. D. Anthers. E. Style arms. F. Achene and pappus. G. Achene indumentum and bisseriated pappus (based on J. N. Nakajima & R. Romero 707). Drawing by Rogério Lupo.

FIGURE 2. Geographical distribution of Chrysolaena glandulosa in southwestern Minas Gerais, Brazil.

FIGURE 3. Light microscopy (LM) and Scanning Electron Microscopy (SEM) photomicrographs of the pollen grains of Chrysolaena glandulosa. Polar view: 1. Optical section (LM). 2. Surface of apocolpium. (SEM). Equatorial view: 3. Optical section (LM). 4. Aperture (LM). 5. Aperture (SEM). 6. Detail of surface (SEM) (based on R. Romero et al. 4577). Photos by Vânia Gonçalves-Esteves.