Florivern Herbarium · Sheet HERB-04
Det. — species determination
Euphorbia trigona
African Milk Tree
Fam.
Euphorbiaceae
Architectural cactiform succulent with trigonous winged stems, paired stipular spines, and ephemeral caducous leaves along the apical ridges.
Hab. — where it grows wild
Dry rocky escarpments of Central and Southwestern Africa (Gabon to Angola)
HERB-04
Characters
Group
Succulents & Cacti
Setting
Indoor / Sheltered Outdoor
Size class
Floor Statement (1.0–2.5 m)
Temperament
Effortless / Resilient
Animals
Toxic if Ingested
Sheet II — Conditions of cultivation
How it has been grown,
and what changes it.
Allow 100% of the mineral substrate column to dry completely between soakings during spring and summer active growth. During autumn and winter low-light periods, restrict water to once every 4–6 weeks just to prevent stem shriveling.
25% – 50% RH (thrives in dry heated indoor air)
15°C – 32°C (60°F – 90°F); protect from frost below 10°C
Air temperature as recorded for this species in cultivation. Cold drafts matter more than the average.
70% mineral grit (pumice, decomposed granite, coarse sand) and 30% sifted organic compost for rapid vertical drainage.
Height 1.2–2.1 m indoors; vertical three-winged succulent stems
Sheet III — Animals and households
If a cat, a dog or a child shares the room
Toxic if ingested
Keep it out of reach of cats, dogs and small children. Place it where chewing is not a habit.
The record
Exudes pressurized white latex sap containing diterpene esters upon stem puncture. Causes dermal blistering, severe ocular inflammation on contact, and mucosal toxicity if ingested by pets or humans.
Florivern is a herbarium and a shop, not a veterinary authority. If you suspect a plant has been eaten, call your veterinarian or an animal poison control line.
Sheet IV — Monograph
Notes toward cultivation
CAM Photosynthesis & Xeric Architecture
Operating via Crassulacean Acid Metabolism (CAM), Euphorbia trigona opens its stomata predominantly at night to fix carbon dioxide with minimal evaporative water loss. Its three-ribbed photosynthetic stems store water in specialized parenchyma tissue, demanding an uncompacted mineral substrate and high daily photon flux.
Not a cactus
Despite its look, this is a succulent spurge from Africa, not a cactus from the Americas. Its paired spines grow from the stem ridges, and small leaves appear along them during active growth and drop when the plant rests. Losing those leaves is normal.
In cultivation
Give it as much light as you can, ideally a bright window with some direct sun. Water thoroughly, then let the mix dry out completely before watering again, and water much less in winter. Tall plants become top-heavy, so use a heavy pot and stake if needed.
Handling the sap
Like all euphorbias, it bleeds a milky latex when cut or broken. The sap can irritate skin and is harmful to eyes, so wear gloves and eye protection when pruning or repotting, and wash hands afterwards.
Propagation and problems
Cuttings root once the cut end has dried and calloused for some days. Stems that turn soft or brown at the base usually indicate rot from too much water; corky brown patches on older stems are often harmless sun or age scarring.
Supplementary plates
Plates show cultivated individuals, not a type specimen. Leaf form, color and habit vary between plants of the same species.
Sheet V — Cited in the Journal
Further reading on this plant
Held in the Store
Specimens and materials
Euphorbia Trigona — Architectural Column
In Stock
$145
Shigaraki Reduction-Fired Cylinder Vessel
In Stock
$120
Each specimen is an individual plant; size and form differ from the plates on this sheet.