Glandulicactus
| Glandulicactus | |
|---|---|
| File:Glandulicactus unicinatus.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cacteae |
| SubTribe | |
| Genus | Glandulicactus |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). Lodé maintains Glandulicactus as a distinct genus from Sclerocactus due to the presence of extrafloral nectaries. |
Etymology
The name is derived from the Latin glandula (gland), referring to the prominent nectar-secreting glands (nectaries) located in the areoles.
Description
Glandulicactus consists of globose to shortly cylindrical cacti, often becoming caespitose (forming clumps) with age.
- Stems: Deeply ribbed, often with a bluish-green or dark green epidermis.
- Areoles: Feature characteristic extrafloral nectaries (glands) located above the spine-bearing part of the areole.
- Spines: Very strong and often hooked, particularly the central spines, which can be remarkably long and colorful (reddish or brownish).
- Flowers: Diurnal and self-sterile, appearing near the apex. They are funnel-shaped and typically dark brownish-red or deep magenta.
- Fruits: Globose to ovoid, slightly fleshy at first but becoming dry at maturity, usually covered with scales.
- Seeds: Relatively large, black, and shiny with a finely pitted (foveolate) surface.
Habitat
The genus grows in Chihuahuan Desert scrublands on rocky limestone or alluvial soils. They are found at altitudes between 600 m and 2400 m, often growing under the protection of nurse plants.
Distribution
- Mexico: Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Tamaulipas, Zacatecas.
- USA: New Mexico, Texas.
Species
Following the classification of Lodé (2015), the genus includes 2 species and 2 subspecies:
Taxonomy
While some modern classifications (e.g., Hunt) include these species within Sclerocactus, molecular studies (Vázquez-Sánchez et al., 2013) suggest they are more closely related to Ancistrocactus. Lodé keeps Glandulicactus separate based on its distinct extrafloral nectaries and specialized floral morphology.
