Oxalis latifolia
(sorrel)

Preferred Common Name

• sorrel

International Common Names

• English: fishtail oxalis (Australia)
• Spanish: trebol de huerta

Local Common Names

• Bolivia: taru taru
• Brazil: trevo
• Colombia: acedera; trebol de jardin; trebol falso
• Cuba: vinagrillo
• Germany: Breitblaettriger sauerklee
• India: khati-buti; phiphru; tipatia weed
• Indonesia: tjalintjing gede
• Madagascar: kodidimborana
• Mauritius: oseille; trefle
• Mexico: acedera; acederilla; trebol
• South Africa: red garden sorrel; rooituinsuring
• Spain: chuminbedderra
• Sri Lanka: puliyarai
• Uganda: katanpuni
• Venezuela: vinagrillo

EPPO code

• OXALA (Oxalis latifolia)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Geraniales
•                         Family: Oxalidaceae
•                             Genus: Oxalis
•                                 Species: Oxalis latifolia

O. latifolia is free of nomenclatural problems, though the botanical authority is sometimes indicated as 'H.B.&K.' instead of 'Kunth'.

A number of Oxalis species are unusual among dicotyledons in producing scaly bulbs. O. latifolia is one of these. The structure of the bulb, 1-2 cm diameter, is complex with two main types of scale which Jackson (1960) refers to as 'membranous' and 'true scales'. Membranous scales are the first to be produced, whether in newly forming bulbils, or at the apex of bulbs resuming growth after dormancy. These scales may or may not produce petioles and leaves from their tips, and have axillary buds which develop into peduncles/inflorescences in larger bulbs, but not in first-year bulbils. After a number of membranous scales have developed, narrower true scales are formed. These true scales have axillary buds which do not develop in the first season but will develop into stolons the following year. At the end of the season, the leaves die down leaving their membranous bases to form a protective layer. When growth resumes, the outermost scales disintegrate, new scales and leaves develop at the apex, while stolons grow out from the axils of the old true scales. Estelita-Teixeira (1982) describes the differences in bulb structure between O. latifolia, O. corymbosa and O. oxyptera. Each bulb produces up to 14 leaves, but with some leaves developing from daughter bulbs, Marshall and Gitari (1988) record up to 45 leaves per plant. There is no stem, other than the short axis of the bulb. The root is a fleshy tuber up to 2 cm in diameter at the top, resembling a small carrot but whitish. Under dry conditions, this root shrinks and contracts, drawing the parent bulb deeper into the soil.

In the typical form of O. latifolia the bulbils are formed at the end of stolons up to 10 cm long, which may number 30 or more. The leaves, on petioles up to 30 cm long, are glabrous, trifoliate, with individual leaflets broadly fish-tail shaped, 3-6 cm across. The leaflets fold along the midrib at night. The peduncles, about the same length, carry an umbel of 5-12 flowers, each flower 10-20 mm across, erect while open but reflexed before and after. The five sepals each have two orange glands at the tip. The five petals are greenish on the outside, a rich purple inside, changing abruptly to become paler towards the base. O. latifolia has the potential for tristyly, having two sets of five stamens of different length but weedy populations are almost invariably short-styled, with medium and long stamens.

In Cornwall (UK), Spain, New Zealand and California, USA, atypical forms (sometimes referred to as 'Cornwall type') occur, with bulbils all sessile (no stolons), leaflets much more rounded (less broadly fish-tailed), and flowers distinctly paler in colour (see Young 1958; Esler, 1962; Robb, 1963). At least two different atypical clones occur in Cornwall. These are also short-styled, with the possible exception of one mid-styled population in New Zealand (Esler, 1962).

When seeds are formed, they are orange to dark yellow, about 1 mm long and ribbed. The capsules have the explosive character of O. corniculata and seeds may be thrown up to 40 cm (Rivals, 1960).

Chromosome number (2n) = 14. Triploid forms are known from Mexico (Holm et al., 1997).

Useful review papers on O. latifolia include those by Holm et al. (1997), Parsons and Cuthbertson (1992) and Marshall (1987).

Holm et al. (1997) record that O. latifolia is a weed of at least 37 countries in at least 30 crops. It is listed as a major weed in India, New Zealand, Australia, South Africa and Uganda, particularly in cassava, maize, upland rice, tea, potato, coffee, cereals, sugarcane, orchards and vegetables. It can achieve dominance under certain intensive cultivation systems which remove other competing weeds, and spread of bulbs. Reports on the competitiveness of, and hence yield reducing potential of O. latifolia are somewhat contradictory. Atwal and Gopal (1972) recorded 56% reduction in maize yield from uncontrolled O. latifolia. However, Thomas (1991) reported no apparent effect on maize yield from populations of 33-50 plants/m² in four successive seasons, when all other weeds had been controlled by a mixture of pre-emergence herbicides. The weed is of undisputed importance in horticultural nurseries where it may infest the produce sold and lead to loss of reputation and occasionally to business closure.

O. latifolia is an alternate host of Puccinia sorghi.