Tacinga
| Tacinga | |
|---|---|
| |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Opuntioideae |
| Tribe | Opuntieae |
| SubTribe | |
| Genus | Tacinga |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). The genus is accepted in a broad sense (s.l.). |
Etymology
The name is an anagram of "Caatinga", the semi-arid region of northeastern Brazil where most species occur.
Description
Tacinga is a genus of bushy, climbing or creeping cacti with variable stem morphology.
- Habit: Shrubby, erect, climbing or lianiform plants.
- Stems: Segmented; cylindrical, elongated or flattened, rounded to elliptic.
- Leaves: Very reduced, cylindrical, deciduous.
- Areoles: Dark, producing easily detachable glochids.
- Spines: 1–6, acicular, sometimes absent or caducous.
- Flowers: Diurnal or nocturnal, self-sterile, near stem tips; pale yellow, greenish, brownish, purplish, orange or red; stamens erect and not sensitive.
- Fruits: Elongated, fleshy, deeply umbilicate; perianth remnants deciduous.
- Seeds: Large (up to 5 mm), globose to pyriform, with leathery aril and hairy funicular envelope.
Habitat
The genus grows mainly in the Brazilian caatinga, in dry forests, rocky outcrops, and among shrubs and other succulents.
Altitude range: from about 20 m up to 1550 m.
Some species (e.g. T. funalis) grow climbing over vegetation, forming dense tangled masses.
Distribution
- South America:
Brazil (Alagoas, Bahia, Minas Gerais, Paraíba, Pernambuco, Rio Grande do Norte, Sergipe), Venezuela (Sucre)
Taxonomy
The genus Tacinga was established by Britton & Rose (1919).
Originally created for species with cylindrical stems, it was later expanded to include taxa with flattened segments previously placed in Opuntia.
Morphological characters such as non-sensitive stamens (in contrast to Opuntia s.s.) are not always reliable due to convergent evolution.
Seed and pollen studies, along with molecular analyses (Griffith & Porter 2009; Majure et al. 2012), support the recognition of Tacinga as a monophyletic genus within Opuntieae.
The genus forms part of a clade including Brasiliopuntia, Consolea, Miqueliopuntia, Nopalea, Opuntia, and Tunilla.
According to Joël Lodé (2015), Tacinga is accepted as a valid genus.
Species
Following the classification of Joël Lodé (2015).
- Tacinga braunii
- Tacinga funalis
- Tacinga inamoena
- Tacinga lilae
- Tacinga palmadora
- Tacinga saxatilis
- Tacinga subcylindrica
- Tacinga werneri
Hybrids
Notes
- The genus includes both cylindrical and flattened stem forms.
- Tacinga lilae represents an extension of the genus outside Brazil.
- Some species show strong ecological specialization to caatinga environments.
- Hybridization occurs in habitat.
