Marshallocereus
From M&J Cactus Wiki
| Marshallocereus | |
|---|---|
| File:Marshallocereus aragonii.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cereeae |
| SubTribe | Echinocereinae |
| Genus | Marshallocereus |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015) with reference to Backeberg (1950), Terrazas (2000), Arias & Terrazas (2006), Nyffeler & Eggli (2010), and Bàrcenas et al. (2011). |
Etymology
Named in honour of William Taylor Marshall (1886–1957), American botanist and co-founder of the Cactus and Succulent Society of America.
Description
Marshallocereus is a genus of vigorous, tree-like columnar cacti.
- Habit: Arborescent; branching from the base; usually without a distinct trunk.
- Stems: Erect, columnar; dark green, shiny; often with waxy coating forming a V-pattern in new growth.
- Ribs: 6–10; thick, rounded.
- Areoles: Small; with brown to grey wool.
- Spines: 4–6 radial spines (short, acicular); 1–3 central spines slightly longer.
- Flowers: Nocturnal; funnel-shaped; self-sterile.
- Flower color: Outer tepals greenish to purplish; inner tepals pinkish-white to deep pink.
- Floral structures: Tuberculate and scaly floral tube.
- Pollination: By bats (e.g. Glossophaga spp.); flowers produce abundant nectar.
- Fruits: Large, ovoid; dry at maturity; dehiscent into segments; with persistent spines.
- Fruit pulp: White or red.
- Seed dispersal: Primarily by birds (ornithochory).
- Seeds: Large, black, smooth, glossy.
Habitat
Occurs in tropical dry environments:
- semi-arid regions
- volcanic landscapes
- dry deciduous forests
- rocky slopes and river margins
- coastal proximity
Altitude range: from sea level to ~50 m (possibly higher).
Distribution
Central America:
- Costa Rica (Guanacaste, Puntarenas)
- El Salvador (Cuscatlán, Sonsonate, San Miguel, La Unión)
- Guatemala (multiple departments)
- Honduras (Yoro)
- Mexico (Chiapas)
- Nicaragua (León, Madriz)
- Panama
Taxonomy
A re-established genus with complex systematic history.
Key points:
- Originally described within Cereus (type: Cereus aragonii)
- Later included in Stenocereus sensu lato
- Morphological and anatomical studies (Terrazas 2000; Arias & Terrazas 2006) indicated separation
- Seed morphology studies (Arroyo-Cosultchi et al. 2006) showed clear differences from Stenocereus
- Similarities noted with Pachycereus, but without sufficient support for inclusion
- Nyffeler & Eggli (2010): clarified broader phylogenetic relationships within Cactaceae
- Guiggi (2012): reinstated Marshallocereus and proposed subspecific treatment
The genus is accepted as distinct in Lodé (2015).
Species
According to Joël Lodé (2015):
Notes
- Represents a lineage formerly embedded in Stenocereus.
- Strong seed morphology signal supporting separation.
- Likely bat-pollinated with bird-dispersed fruits.
- Possible broader distribution than currently confirmed.
- Widely used locally for living fences (quickset hedges).
