Agave macroacantha Zucc.
Black-spined Agave
Agave macroacantha, known as black-spined agave for its striking jet-black terminal spine, is a species endemic to the arid valleys of Oaxaca and Puebla in Mexico, where it grows between 1,200 and 2,000 m a.s.l. in xerophytic scrubland on stony soils. It is one of the most prized agaves in ornamental horticulture worldwide, thanks to its combination of glaucous (blue-grey) leaves contrasted against a completely black terminal spine, giving it a unique sculptural appearance. It forms compact to medium, perfectly symmetrical rosettes, making it ideal for containers, cactus gardens, and contemporary xeric design. Being monocarpic, it flowers only once after many years of growth, producing a scape up to 4 m tall with yellowish-green flowers, after which the mother plant dies.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Overview
| Category | Classification |
|---|---|
| Family | Asparagaceae |
| Genus | Agave |
| Growth Habit | Compact to medium rosette (50–80 cm diameter), perfectly symmetrical, acaulescent, monocarpic. Slow growing. Produces few basal offsets. |
| Conservation Status | Vulnerable (VU) in wild populations due to overcollection for the ornamental trade and habitat loss in Oaxacan and Poblano valleys. |
| pH Target | 6.5–8.0 |
| Type | Sandy-loam to stony, very well drained, low in organic matter |
Origin & Habitat
Morphology
Lanceolate, 30–50 cm long and 3–5 cm wide, glaucous blue-grey with a fine surface wax. Margin with small, grey, regularly spaced corneous teeth. Prominent terminal spine 3–5 cm, jet black — the diagnostic character of the species.
ecoYellowish-green to violet-tinged at the tip, 5–7 cm long, in a dense panicle on a scape 3–4 m tall. Appear only once at the end of the plant's life, generally between 10 and 20 years.
ecoAcaulescent. The rosette develops directly from the base with no visible stem. The central piña is small (3–8 kg) compared to larger agaves.
ecoFibrous, shallow, and spreading. Adapted to capture scarce rainfall in the stony soils of dry Oaxacan valleys.
ecochevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Requirements
Soil & Substrate
Type
Sandy-loam to stony, very well drained, low in organic matter
groups Beneficial Associations
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Propagation Strategy
B
E
Every 3–4 years. Transplant carefully to avoid damaging fibrous roots. Prefer terracotta pots that facilitate evaporation.
One very light annual fertilization in spring with low-nitrogen mineral fertilizer (cactus formulation). Never fertilize in autumn-winter.
Uses & Applications
Precautions / Toxicity
Moderate. The black terminal spine is extremely piercing. Sap may cause skin irritation in sensitive individuals. Wear gloves when handling.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Plant Health
Base rot (Fusarium spp., Phytophthora spp.) from overwatering
Mealybugs (Pseudococcus spp.)
Agave snout weevil (Scyphophorus acupunctatus)
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
"One of the most cultivated Agave species in European and Japanese collections for its compact size and sculptural appearance. The black colour of the terminal spine is so characteristic that it is impossible to confuse with other species. Wild plants are under pressure from illegal collection; always purchase from nurseries with propagation certification."
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Scientific Integrity
🟡 MediumVote to help validate this record
Sources
Loading…
Discussion
Disclaimer
This species record is provided for educational and informational purposes only. Jardín Roca Negra does not guarantee the accuracy or completeness of the data. Content is community-curated and may be subject to revision; it should not replace advice from a qualified botanist. This species may be toxic, invasive, or subject to legal restrictions — verify before handling or cultivating. Jardín Roca Negra accepts no liability for any harm arising from reliance on this information. Images are reproduced under Creative Commons or equivalent free licenses; credits are noted below each image.