Species · genus Aloe · Asphodelaceae
Flat-flowered Aloe
Aloe marlothii A.Berger
Also known as: Mountain Aloe · Transvaal Aloe · Tree Aloe
Cultivars of A. marlothii
The named forms growers keep — each with its own page, each honest about how much we know.
No named cultivars catalogued under A. marlothii yet. When growers document a stable, named form, it earns its own page here.
Guide
The species-level account. Cultivar pages build on this and say where they differ.
A Towering Mountain Aloe
Aloe marlothii, known as the mountain aloe, is a large tree-like succulent that can reach up to 4 metres in height. It forms a robust, fleshy rosette of silver-green leaves armed with thorns, and in summer sends up spectacular yellow-orange flowers on branches held almost horizontal from the main flower stem.
Source: RHS
Roots in Southern Africa
This species belongs to the family Asphodelaceae and is native to a stretch of southern Africa running from south-eastern Botswana through Eswatini, Mozambique and the Northern Provinces to KwaZulu-Natal, with populations also established in the Free State. It is a plant of the desert and dry shrubland biome, and it was first described by A. Berger in 1905.
Source: Kew
Sun, Grit and Restraint
Mountain aloe wants full sun and a well-drained loam, whether that means a south- or west-facing spot outdoors in a sheltered position, or a peat-free cacti or loam-based potting compost with added grit indoors. Water it moderately while it is in growth, but hold back sharply once it goes dormant. A general liquid fertiliser applied monthly from May to August is enough to support it through the growing season.
Source: RHS
Seed, Cuttings or Plantlets
This aloe can be raised from seed, from leaf cuttings, or simply by separating the plantlets that form at its base.
Source: RHS
Armour and Architecture
What distinguishes this aloe is its scale and structure: a clump-forming, evergreen habit that builds into something closer to a small tree than a typical houseplant succulent, with very thorny leaves and an architectural silhouette. Its flowers, held on near-horizontal branches, add a distinctive tiered look above the rosette.
Source: RHS
Scale and Mealybug Watch
Keep an eye out for scale insects and mealybugs, the two pests most likely to trouble this aloe.
Source: RHS
Little Pruning Needed
No pruning is required for this plant, and it is generally free of disease. In milder southern counties it can even tolerate brief spells down to -6°C outdoors, provided the roots stay dry through that cold.
Source: RHS
Care recipe
The species record — the baseline every cultivar inherits unless it says otherwise.
Care notes are early — not yet verified
- Light
- ai:claude-opus-4-8
- Water
- ai:claude-opus-4-8 (range 14-28d)
- Humidity
- ai:claude-opus-4-8
- Soil
- ai:claude-fable-5
- Care
- ai:claude-fable-5
Direct sun
≈ every 28 days
Low — average room
7–30 °C
Gritty, fast-draining cactus and succulent mix
Grown from seed; a slow-maturing tree aloe
Light succulent feed once or twice in spring and summer
Slow
Tall branched orange spikes on mature plants, rare indoors
Toxic to cats & dogs
Saponins + anthraquinones (the latex) — vomiting, lethargy, diarrhoea. This is where toxicity lives: every cultivar of this species inherits it and none can override it.
Reference images
Every image credited. Licenses link to their deeds.
PrimarySources: ai:claude-opus-4-8 · ai:claude-opus-4-8 (range 14-28d) · ai:claude-fable-5 · ASPCA
Kept true by its growers
Every fact here carries its source. Grow Flat-flowered Aloe yourself? What you’ve observed — how it drinks, how it holds its color, a name that’s off — and a clear photo of your plant are exactly what keep this page honest. Contributions are reviewed before anything changes.
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