Gaylussacia chamissonis Meisn.,

Garcia, Lívia & Jr, José Nascimento, 2024, Ericaceae from Serra de São José and Serra do Lenheiro, Minas Gerais, Brazil, Rodriguesia (e 00832024) 76, pp. 1-12 : 10

2.2. Gaylussacia chamissonis Meisn., Fl. bras. 7: 144. 1863. Fig. 4 h-m

Shrub 0.5–1 m tall; branches tomentose; non-glandular trichomes on branches, leaves, inflorescences, bracts, flowers, and fruits; glandular trichomes absent; clavate or capitate glands, yellow, present on leaves and branches. Leaves with brochidodromous venation, petiolate, robust petiole, 1–1.5 × 0.5–1 mm, leaf blades chartaceous to coriaceous, narrowly elliptical, 12–20 × 3.0– 6 mm, apex obtuse to rounded, mucronate, base acute to obtuse, margin strongly revolute, entire, adaxial surface densely pubescent, denser trichomes on the central vein, abaxial surface densely pubescent, denser trichomes on the central vein. Inflorescence axillary raceme, peduncle ca. 5 mm, rachis 1.5–2.5 cm long, tomentose; bracts and bracteoles elliptical or oval. Pedicel ca. 1 mm long; calyx lobes 1.2–1.5 × 1.5 mm, densely pubescent; corolla approximately 5–6.5 × 3–4 mm, white, campanulate, pubescent at the angles; style 4–5mm long, glabrous, 10 stamens with filaments ca. 1 mm long, sparsely pubescent, anthers 2–2.5 mm long. Fruits not observed.

Examined material: Tiradentes , Serra de São José, rock field close to the city, 6.XII.1983, fl., M. Leitão-Filho 15162 ( ESA, ESAL, UEC); trail to Carteiro, 20.X.2023, fl., JE Nascimento-Jr 1835 ( HUFSJ) .

Gaylussacia chamissonis occurs exclusively in the Southeast region of Brazil in mountainous vegetation associated with rocky outcrops (campos de altitude e campos rupestres) at elevations ranging from 1,200 to 2,500 meters ( Romão 2011). The species flowers and bears fruit in the region at least from August to December.

Gaylussacia chamissonis closely resembles Gaylussacia pallida Cham. in terms of habit, trichome distribution and density, and leaves with capitate glands and strongly revolute margins. This similarity renders the differentiation between the two species a challenging task, especially considering the significant overlap among distinctive characteristics pointed out by Romão (2011). The only nonoverlapping trait between the species, as identified by Romão (2011), is the position of non-glandular trichomes, which are patent in G. chamissonis and not patent in G. pallida (only when considering specimens of G. pallida occurring outside the Serra do Caparaó, between the states of Minas Gerais and EspÍrito Santo). Therefore, further studies are imperative to gain a better understanding of the circumscription between these two species.

Figures

Figure 4 – a-m. Species of Gaylussacia – a-c. Gaylussacia brasiliensis – a. branch with racemose inflorescences; b. flowers after anthesis; c. immature fruits; d-g. Gaylussacia montana – d. habit; e. branches with axillary racemose inflorescences; f. flowers after anthesis; g. glandular trichomes on the hypanthium and calyx; h-m. Gaylussacia chamissonis – h. branch with axillary racemose inflorescences, with immature fruits detailed in the bottom right corner; i. leaves with strongly revolute margins; j.leaf with abaxial surface bearing yellow glands and non-glandular white trichomes; k. lateral view of flowers after anthesis; l. frontal view of flowers after anthesis; m. stamens with filaments bearing yellow glands and non-glandular white trichomes.Photographs: c. Marcos Sobral; all other photographs are by the authors.