Sheep's Sorrel
Rumex acetosella
NEMBA category
English: Sheep's Sorrel, Red Sorrel, Field Sorrel, Sour Weed
Afrikaans: Skaapsuuring, Rooisuuring
Rumex acetosella, commonly known as Sheep's Sorrel, is a small, slender, perennial herbaceous plant that often forms dense patches. Its most distinctive features are its arrow-shaped or spearhead-shaped leaves, which are typically bright green but often turn reddish, especially in full sun or nutrient-poor soils. The plant often has reddish stems and produces tall, slender, reddish-brown flower stalks topped with inconspicuous reddish-green flowers that later develop into reddish-brown seeds, giving infested areas a rusty appearance.
This plant is a widespread invasive species in South Africa, particularly in disturbed areas, pastures, and natural grasslands, as it spreads aggressively via underground stems (rhizomes) and abundant seeds, out-competing indigenous ground-cover and indicating poor, often acidic, soil conditions.
Have you got a better picture?
If you don't mind us using it, please upload it by clicking the Upload button below (you must be logged in to do this)
Origin:
Native to Eurasia and North America.
Distinguishing features:
Arrow-shaped (hastate) leaves: Leaves are typically 2-6 cm long, with two pointed lobes at the base, resembling an arrow or spearhead. They can be green or reddish.
Often reddish stems and flower stalks: The plant, especially its slender, upright flower stems, frequently displays a distinct reddish or rusty colour.
Forms dense mats: Spreads rapidly by underground rhizomes, creating dense, low-growing patches that can exclude other plants.
Inconspicuous reddish-green flowers: Small flowers are borne in slender, upright clusters on tall stalks, often appearing reddish or brownish.
Prefers acidic soils: Its presence often indicates acidic or poor soil conditions, which it can further acidify.
Overall appearance:
A slender, upright herbaceous plant that often forms dense, low-growing mats or patches. It is commonly recognised by its arrow-shaped leaves and reddish colouration, especially when it goes to seed.
Height:
Typically grows 10 to 40 centimetres tall, but can sometimes reach up to 60 centimetres, especially its flower stalks.
Width:
Forms dense, spreading patches or mats that can extend over several square metres due to its creeping rhizomes.
Leaves:
Mainly basal (growing from the base of the plant), alternate, and very distinctive: arrow-shaped or spearhead-shaped (hastate), 2 to 6 centimetres long, with two pointed lobes that flare outwards at the base. They are typically bright green but often turn reddish or purplish, especially in full sun or when stressed. The leaves have a sour, tangy taste.
Flowers:
Very small, inconspicuous, and reddish-green. Male and female flowers are borne on separate plants (dioecious), in slender, upright, branched clusters (panicles) at the top of thin stems. Male flowers are yellowish-green, and female flowers are reddish.
Flowering season (South Africa):
Mainly flowers in spring and summer (around September to March), but can flower almost year-round in favourable conditions.
Fruits:
Very small, reddish-brown, three-angled achenes (dry, single-seeded fruits), about 1-1.5 millimetres long. They are numerous and contribute to the reddish appearance of the plant when seeding.
Seeds:
Extremely small, dull, reddish-brown, three-angled seeds, about 1-1.5 millimetres long. They are produced in large quantities and can remain viable in the soil for a long time.
Bark:
Not applicable, as it is a herbaceous plant. Stems are slender and often reddish.
Roots:
Develops an extensive system of slender, creeping, yellowish rhizomes (underground stems) that spread horizontally, giving rise to new plants and forming dense colonies. It also has a taproot.
Soil type:
Highly tolerant of a wide range of soil conditions, but particularly thrives in poor, disturbed, compacted, and especially acidic soils (indicating low pH and often low fertility). It is often found in sandy or gravelly soils.
Aspect:
Prefers full sun but can tolerate partial shade. It is very hardy and tolerant of frost, drought, and often found in open, exposed areas. Its presence can indicate soil degradation.
Edibility:
The leaves have a pleasant sour, lemony taste and are edible in small quantities. They are used in salads, soups, or as a garnish.
Toxicity:
Contains oxalic acid (the compound that gives it its sour taste). While safe in small quantities, consuming large amounts can be toxic due to the oxalic acid interfering with calcium absorption, potentially leading to kidney damage or other issues, especially in livestock.
Uses:
Historically used as a wild edible for its tart leaves, a source of Vitamin C, and in traditional medicine for its diuretic and cooling properties.
Ecology:
As an alien invasive plant in South Africa, Rumex acetosella is a widespread problem, particularly in grasslands, fynbos, pastures, disturbed areas, and along roadsides. It forms dense, low-growing mats that outcompete and exclude indigenous grasses and herbaceous plants, reducing biodiversity. Its aggressive spread via rhizomes and prolific seed production make it very difficult to control. It thrives in and can further contribute to the acidification of soils, creating conditions less favourable for many native species. It is considered an indicator of poor soil health.
Distribution and habitat:
Widely naturalised and invasive throughout most of South Africa, particularly common in the higher rainfall, temperate, and montane regions, and areas with acidic or disturbed soils. It is very widespread in the Eastern Cape (common around Kenton-on-Sea in disturbed sites, grasslands, and fynbos), Western Cape, KwaZulu-Natal, Mpumalanga, Limpopo, Free State, and Gauteng. It invades grasslands, fynbos, rangelands, pastures, cultivated lands, roadsides, disturbed areas, and open woodlands.
Derivation of name:
The genus name Rumex is the classical Latin name for docks or sorrels.
The species epithet acetosella is a diminutive of 'acetosa', meaning 'sour', referring to the sour taste of its leaves due to oxalic acid, and 'ella' meaning 'little'.
"Sheep's Sorrel" likely refers to its edibility by sheep and its prevalence in pastures.
Historical aspects:
Sheep's Sorrel was introduced to South Africa accidentally, likely as a contaminant in crop seeds or livestock feed, or deliberately for its edible and medicinal properties, many centuries ago. Its adaptability, ability to thrive in disturbed and poor soils, and its efficient reproductive strategies (both vegetative and by seed) allowed it to escape cultivation and become a widespread invasive weed, particularly impacting agricultural and natural grazing lands.
Interesting facts:
This plant has leaves shaped like tiny arrows or spearheads – it's like a mini-archer in the plant world!
Ever tasted something super sour and lemony that came from a plant? That's this one! Its leaves are known for their tangy flavour, but remember, only a little bit!
This plant is a bit of a trickster; it can make whole fields look rusty-red when it goes to seed, which is actually a pretty cool natural spectacle!
If you see lots of this plant, it's often a sign that the soil is a bit grumpy (acidic) and might need some help!
Friendly alternatives:
Common name
Scientific Name
Plant type:
Plant type
Plant family:
Plant family (derivation)