Tacinga saxatilis

Name and scope of the description

Tacinga saxatilis (formerly Opuntia saxatilis) is an accepted species. Detailed dimensions and new sites in the description below come from the revision from 2023 and refer to the typical subspecies, T. saxatilis subsp. saxatilis. This distinction matters when comparing data with descriptions of the second subspecies, T. saxatilis subsp. estevesii. [Gonzaga et al. 2023] [2-WWW]

Stems, flowers and fruits

In the material studied, plants formed shrubs 20–80 cm tall, without a distinct single trunk. The flattened segments were 8,7–16,5 cm long, 4,2–8 cm wide and 6–7 mm thick. Areoles, 1–3 mm in diameter, were spaced 3–11 mm apart. They produced one to five whitish or greyish spines, 5–16 mm long, of varying stiffness. [Gonzaga et al. 2023]

Flowers are yellow. The described perianth was about 11 mm long, and the green, club-shaped pericarpel was 18–20 mm long and about 10 mm wide. Its areoles bore hairs, glochids and flexible spines. Separating the dimensions of the perianth and pericarpel allows the size of the whole flower to be read correctly. [Gonzaga et al. 2023]

Fruits are 2,2–3 cm long and 1,7–2,3 cm wide, globular to slightly flattened, with a small apical projection. Initially green, they become wine-coloured at maturity. The pulp remains translucent. Seeds, 3–5 mm long, have a shape compared with a shell and are surrounded by a fibrous covering. [Gonzaga et al. 2023]

Limestone outcrops and new sites

The account from 2023 confirmed material from Formosa, São Domingos and Alvorada do Norte in Goiás, and Novo Jardim in Tocantins. Plants grew at 430–850 m elevation, at the base or on the middle parts of limestone outcrops. The sites lie within the Cerrado, surrounded by shrub and forest vegetation. Documentation was based on herbarium specimens and field observations. [Gonzaga et al. 2023]

Fruiting plants were recorded during the rainy season. The authors identified rock extraction, grazing and land transformation as local factors affecting the sites. The new data expand the known range of the subspecies while also showing the importance of small, isolated rocky habitats. [Gonzaga et al. 2023]