Tacinga lilae

From Opuntia to Tacinga

Tacinga lilae (formerly Opuntia lilae) was transferred to its current genus in 2013. The study used material propagated from the type collection Trujillo and Ponce 18643 from Sucre. Plastid and nuclear data placed the plant in the Tacinga clade, and morphological comparison showed agreement in features including embryo shape, fruit apex structure and epidermis. [Majure et al. 2013]

In the tree studied, T. palmadora occupied the closest position, with moderate support for this node. The species differ in size, floral details and ploidy level. T. lilae has 2n = 66, while T. palmadora has 2n = 22. Earlier inclusion of Opuntia lilae within O. curassavica was challenged by the results of this analysis. [Majure et al. 2013]

Growth form, stem segments and flowers

Plants have an upright habit and reach 0,4–1,2 m. Segments are elliptic to narrowly elliptic, 1,8–11 cm long and 1–4 cm wide. Areoles are about 12 mm apart. Each produces 2–7 spines, 1–2 cm long. Compared with T. palmadora, smaller segment and tepal dimensions are particularly useful. [Majure et al. 2013]

Flowers are red-orange. Outer tepals are about 4 mm long, and inner tepals 9–10 mm. The stamens remain within the perianth. Under the microscope, segment surfaces reveal stomatal apparatuses raised above the surrounding epidermal cells, one of the characters supporting this plant’s placement in Tacinga. [Majure et al. 2013]

Fruits, seeds and reproduction

Fruits are barrel-shaped, nearly globular to obconical, with pink-red pulp. The comparative description reports 20–30 seeds per fruit. The fruit apex has a deep, narrow depression. The seed contains a hook-shaped embryo and perisperm, and its outer covering of funicular origin is hairy. [Majure et al. 2013]

Mature fruits can produce shoots, becoming vegetative propagules. The authors’ observations indicate a substantial contribution from this recruitment pathway. For new plants arising from seeds, the extent of sexual reproduction and possible apomixis remains to be established. The presence of seeds or regenerating fruits describes separate stages and mechanisms of recruitment. [Majure et al. 2013]

Distribution and geographic history

The species is known from Venezuela, in Lara and Sucre, from wild and cultivated material. About 3000 km separates it from the Brazilian part of the genus’ range. The authors of the study from 2013 considered former connections between dry vegetation formations and long-distance dispersal. Each scenario requires further geographical and phylogenetic data. [Majure et al. 2013] [2-WWW]