Haworthiopsis nigra (Haw.) G.D.Rowley
Black Haworthiopsis
Black Haworthiopsis is one of the darkest and most atypical species in the genus, native to the arid gorges of the South African Karoo. Its leaves are so dark green that in full sun they appear almost black, with an extremely rough texture of hard conical tubercles and an overall appearance recalling porous volcanic rock rather than a living plant.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
© Albert01SN
CC BY-SA 4.0
Overview
| Category | Classification |
|---|---|
| Family | Asphodelaceae |
| Genus | Haworthiopsis |
| Growth Habit | Acaulescent to subcaulescent; rarely caespitose; usually solitary or in small groups. |
| Conservation Status | Least Concern (IUCN). Specialist in quartzite and shale microhabitats. |
| pH Target | 5.5 – 7.0 |
| Type | Very poor porous mineral soil, analogous to pulverised quartzite; neutral to slightly acid pH. |
Origin & Habitat
Morphology
Triangular leaves 5–12 cm, very dark green (nearly black under intense sun) with hard dense conical tubercles on both surfaces; margins with dark teeth. Texture is the roughest in genus Haworthiopsis.
ecoVery short or invisible stem; in old specimens a pseudo-trunk of 5–10 cm may develop. Very rarely produces offsets.
ecoInflorescence 15–25 cm; white flowers with green stripes, bilabiate; spring flowering.
ecoFibrous root system, relatively deep for its size, with fleshy storage roots allowing survival in rock crevices with minimal substrate.
ecochevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Requirements
Soil & Substrate
Type
Very poor porous mineral soil, analogous to pulverised quartzite; neutral to slightly acid pH.
groups Beneficial Associations
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
Propagation Strategy
- 1 Remove plant in spring; H. nigra produces basal offsets regularly.
- 2 Detach with a sterile blade; rootless offsets also root well.
- 3 Callus for 1–2 days.
- 4 Plant in draining mineral mix; water after 7 days.
- 1 Remove dark basal leaves with the complete base.
- 2 The rough texture of H. nigra makes it hard to obtain a clean base; use a fine scalpel.
- 3 Callus for 3–5 days.
- 4 Rest on moist mineral substrate; roots in 8–14 weeks.
The near-black leaf color intensifies with good indirect light; in excessive shade they turn greenish.
Interpreting the dark leaf color as a sign of disease or lack of light.
Every 2–3 years in spring. Slow growth; may need less frequent repotting than other Haworthiopsis.
Low-N fertilizer at 50% once a month from March to September. No fertilization in winter.
Uses & Applications
Precautions / Toxicity
Non-toxic or very low toxicity for humans and pets.
chevron_right edit_note Proposed edits auto-approved at +3 net votes
No pending proposals for this section.
"H. nigra displays the darkest leaf colour in the genus and probably in the entire family Asphodelaceae, attributed to high epidermal flavonoid concentrations acting as a UV screen in the high-irradiance Karoo environment. The species rarely produces offsets, making vegetative propagation difficult and the plant scarce in the trade."
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.