Polaskia
From M&J Cactus Wiki
| Polaskia | |
|---|---|
| File:Polaskia chichipe.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Phyllocacteae |
| SubTribe | Echinocereinae |
| Genus | Polaskia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015) with reference to Gibson & Horak (1978), Terrazas (2000), and Hernández-Hernández et al. (2011). |
Description
Polaskia is a genus of arborescent, candelabra-forming cacti.
- Habit: Tree-like; densely branched; candelabriform.
- Height: Up to ~5 m.
- Stems: Light green to yellowish-green.
- Ribs: 7–12; triangular; often slightly sinuous.
- Areoles: Situated in depressions along ribs.
- Spines: 3–8 radial spines; central spines usually absent.
- Flowers: Diurnal, remaining open at night; self-sterile.
- Flower shape: Tubular to funnel-shaped or bell-shaped.
- Flower color: White to creamy white; sometimes tinged pink or greenish-yellow.
- Pollination: By bees (Hymenoptera), hummingbirds, bats, and occasionally sphingid moths.
- Fruits: Small, spherical, berry-like; fleshy and juicy; dark red when ripe; edible.
- Seeds: Small; hat-shaped; black; matte; tuberculate and striate.
- Seed dispersal: By birds and small mammals.
Habitat
Occurs in xerophytic environments:
- dry scrub (matorral)
- plains and steep slopes
- clay and limestone soils
- associated with spiny shrubs and other succulents
Altitude range: approximately 1500–2300+ m.
Distribution
Mexico:
- Oaxaca
- Puebla
Taxonomy
A genus with a history of reclassification based on morphology and molecular data.
Key points:
- Originally described as Cereus species (1905)
- Later split into Heliabravoa and Polaskia (Backeberg, 1949)
- Unified under Polaskia by Gibson & Horak (1978)
- Temporarily included in Myrtillocactus (Hunt & Taylor, 1990)
- Later re-separated (Hunt, 1999)
- Molecular studies (Terrazas, 2000; Hernández-Hernández et al., 2011) confirm distinct monophyletic status
- Shows affinities with both Myrtillocactus and Stenocereus
The genus is accepted as distinct in Lodé (2015).
Species
According to Joël Lodé (2015):
Notes
- Considered a relatively "primitive" lineage within its group.
- Economically important locally due to edible fruits.
- Exhibits broad pollination strategy (insects, birds, bats).
- Phylogenetically positioned between Stenocereus species in some analyses.
- Morphologically similar to Myrtillocactus, but genetically distinct.
