Siccobaccatus
From M&J Cactus Wiki
| Siccobaccatus | |
|---|---|
| File:Siccobaccatus dolichospermaticus.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cereeae |
| SubTribe | |
| Genus | Siccobaccatus |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015) with molecular insights from Aona (2003), Machado et al. (2006), and Nyffeler & Eggli (2010). |
Etymology
The name means "dry fruit" (siccus = dry, bacca = berry), referring to the characteristic dry fruits of the genus.
Description
Siccobaccatus is a genus of columnar cacti with a distinctive cephalium and dry fruits.
- Habit: Erect, usually solitary columnar stems.
- Stems: Bluish; with a strongly woody vascular cylinder.
- Cephalium: Continuous, deeply sunken, developing when stems exceed ~1 m; densely covered with white wool and long yellow to reddish bristles.
- Areoles: Ovate, densely woolly.
- Spines: Acicular, straight, well-developed especially at the base.
- Flowers: Nocturnal, funnel- to bell-shaped, ivory-white; self-sterile.
- Pollination: Primarily by bats (e.g. Monophyllus redmani, Phyllonycteris poeyi).
- Fruits: Initially embedded in the cephalium; bluish, thin-walled, dry at maturity; basally dehiscent.
- Seeds: Brown, very elongated, with cellular testa.
- Dispersal: Likely anemochorous in some species (e.g. S. dolichospermaticus).
Habitat
Endemic to Brazilian dry regions:
- rocky substrates and limestone outcrops (Bambuí formation)
- caatinga vegetation and edges of dry tropical forests
- often forming dense populations
Altitude range: approximately 400–760 m.
Cephalia are consistently oriented toward the northwest.
Distribution
Endemic to Brazil:
- Bahia
- Distrito Federal
- Goiás
- Minas Gerais
- Tocantins
Taxonomy
The genus is currently accepted based on morphological and molecular evidence.
Key points:
- Originally segregated by Braun & Esteves (1990)
- Previously included in Micranthocereus (Ritter, 1979)
- Aona (2003): demonstrated polyphyly of Micranthocereus
- Machado et al. (2006): placed Siccobaccatus as sister to Coleocephalocereus
- Nyffeler & Eggli (2010): supported recognition as a separate genus
The genus is therefore considered distinct and monophyletic.
Species
Currently three recognized species:
Notes
- Distinguished by its dry fruits — unusual within Cactaceae.
- Formerly treated as part of Micranthocereus, now clearly separate.
- Cephalium orientation may have ecological significance.
- Restricted distribution makes the genus of conservation interest.
