Pleiospilos bolusii (Hook.f.) N.E.Br.
African Living Rock / Living Rock Cactus
Pleiospilos bolusii, known as the "African living rock," is a succulent in the Aizoaceae family endemic to the South African Karoo, primarily in the Northern and Eastern Cape provinces. Its grey-brown leaves replicate quartzite rock fragments with stunning accuracy. The species was described by N.E. Brown in honor of pioneering botanist Harriet Margaret Louisa Bolus.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
© Hectonichus
CC BY-SA 3.0
Overview
| Category | Classification |
|---|---|
| Family | Aizoaceae |
| Genus | Pleiospilos |
| Growth Habit | Very slow-growing acaulescent perennial succulent, normally bearing 1 leaf pair; may clump over time. |
| Conservation Status | Least Concern (LC) per IUCN; however, it is a frequent target of illegal collection for the succulent trade. |
| pH Target | 6.0 – 7.2 |
| Type | Quartzitic and schistose Karoo substrate, nutrient-poor, with near-instantaneous drainage; no organic retention. |
Origin & Habitat
Morphology
Leaves are very large compared to other species in the genus, reaching 8–10 cm in length, with a densely dotted surface (translucent windows) that maximizes light capture within the tissue. Color ranges from dark brown to blue-grey depending on light and water conditions.
ecoExtremely short stem, almost entirely buried, supporting the fused leaf pair at the base. Rarely produces more than one active leaf pair simultaneously under natural conditions.
ecoFlowers are especially large for the genus, reaching 7–9 cm in diameter; petals are numerous, narrow, and bright yellow to orange, with a sweet scent. Anthesis occurs only during hours of intense solar radiation.
ecoFleshy, robust roots that can penetrate 20–30 cm deep in stony soils. The root system acts as a secondary reservoir of water and nutrients during the Karoo's prolonged dry season.
ecochevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Requirements
Soil & Substrate
Type
Quartzitic and schistose Karoo substrate, nutrient-poor, with near-instantaneous drainage; no organic retention.
groups Beneficial Associations
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Propagation Strategy
- 1 Sow on the surface of very fine, sandy mineral substrate that is barely moist, without covering the seeds.
- 2 Maintain temperature of 18–25 °C with day/night fluctuation; P. bolusii responds well to thermal changes for germination.
- 3 Cover with clear glass or plastic; ventilate daily to prevent fungal issues.
- 4 Seedlings emerge in 2–4 weeks; gradually remove the cover.
- 5 Transplant individually at 6–12 months when manageable.
- 1 Divide at the start of autumn when the plant resumes active growth and has 3 or more heads.
- 2 Remove the plant and carefully clear substrate from the roots — P. bolusii has especially thick roots.
- 3 Separate heads with a sterilized knife, ensuring each division has roots.
- 4 Callus cut surfaces for 1–2 days and replant in very well-draining mineral substrate.
- 5 Do not water for one week after replanting.
Water only during active growth in autumn-winter; never water while old leaves are being absorbed by new ones.
Watering in summer when the plant is semi-dormant, causing fatal rot.
Every 3–4 years at the start of autumn. Its thick roots need pots that are not too small; use shallow terracotta.
No fertilization, or very sporadic (once per growing season) with heavily diluted cactus fertilizer.
Uses & Applications
Precautions / Toxicity
No known toxicity reported; considered safe in home collections although ingestion is not recommended.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
"P. bolusii is one of the largest-leaved species in the genus; its size has historically caused taxonomic confusion with P. nelii, distinguished mainly by P. bolusii's greater leaf size and larger-diameter flowers. Observing its foliar "windows" in cross-section reveals a light-conducting system toward the internal photosynthetic parenchyma."
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.