Diplazium esculentum
(vegetable fern)

Preferred Scientific Name

• Diplazium esculentum (Retz.) Sw.

Preferred Common Name

• vegetable fern

Other Scientific Names

• Anisogonium esculentum (Retz.) C.Presl
• Anisogonium serampurens C.Presl
• Asplenium ambiguum Sw.
• Asplenium esculentum (Retz.) C.Presl
• Asplenium malabaricum Mett.
• Asplenium moritzii Mett.
• Asplenium pubescens Mett.
• Asplenium vitiense Barker
• Athyrium ambigua (Sw.) Milde
• Athyrium esculentum (Retz.) Copel.
• Callipteris ambigua (Sw.) T.Moore
• Callipteris esculenta (Retz.) J.Sm. ex T.Moore & Houlston
• Callipteris malabarica J.Sm.
• Callipteris serampurens Fée
• Digrammaria ambigua (Sw.) C.Presl.
• Digrammaria esculenta J.Sm.
• Diplazium malabaricum Spreng.
• Diplazium pubescens Link
• Diplazium serampurens Spreng.
• Diplazium vitiense Carruth.
• Gymnogramma edulis Ces.
• Hemionitis esculenta Retz.
• Microstegia ambigua (Sw.) C.Presl.

International Common Names

• English: edible fern; fiddle head fern
• French: fougère végétale

Local Common Names

• Bangladesh: dheki shak; paloi shak; teria shak
• China: cai jue
• India: denkir shaak; dhekia; dhekishak; howkapada-ow; lindra; lingri; luglugi; maikhando; ningru; okang; paloi; paloi saag; sikiomamoidu
• Indonesia: paku-sayur
• Japan: kuware-shida
• Malaysia: paku tanjung; pucuk paku
• Nigeria: akwukwo nni
• Philippines: pacó; pako
• Thailand: phak khut
• USA: hoi’o
• Vietnam: rau don

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Pteridophyta
•             Class: Filicopsida
•                 Order: Polypodiales
•                     Family: Athyriaceae
•                         Genus: Diplazium
•                             Species: Diplazium esculentum

Diplazium is a pantropical fern genus of about 350 to 400 species. The delimitation of the genus has been the subject of some debate, with some authors segregating Diplazium into various genera. Wei et al. (2013) proposed keeping all the species in Diplazium and recognising four subgenera (Pseudallantodia, Diplazium, Sibirica and Callipteris) based on DNA, morphological and geographic evidence.

Diplazium esculentum is regarded as the most important edible fern worldwide (Useful Tropical Plants, 2020). The epithet ‘esculentum’ is from the Latin for ‘edible’, in reference to its use as a food source (Flora of New Zealand, 2020). 

The following description is from Flora of China Editorial Committee (2020):

Rhizome erect, up to 15 cm tall, densely scaly; scales brown, narrowly lanceolate, ca. 10 × 1 mm, thin, toothed at margin; fronds caespitose. Fertile fronds 60-120 cm; stipe brown-stramineous, 50-60 cm, 3-5 mm in diam. at base, sparsely scaly, upward glabrous or hairy; lamina 1-pinnate or 2-pinnate, deltoid or broadly lanceolate, 60-80 cm or longer, 30-60 cm wide, apex acuminate; pinnae 12-16 pairs, alternate, ascending, lower pinnae stipitate, broadly lanceolate, 16-20 × 6-9 cm, pinnatilobate or 1-pinnate; upper pinnae subsessile, linear-lanceolate, 6-10 × 1-2 cm, base truncate, margin serrate or pinnatilobate (lobes minutely serrate), apex acuminate; veins per lobes pinnate, veinlets 8-10 pairs, ascending, lower 2 or 3 pairs usually conjoined. Lamina stiffly herbaceous, glabrous or hairy, rachis glabrous or hairy; costae shallowly grooved, glabrous or occasionally with light brown short hairs. Sori mostly linear, slightly curved, from near midribs to laminar margin; indusia yellow-brown, linear, membranous, entire. Spore surface with large granular or tuberculate projections.

Diplazium esculentum is widely used in Asia and Oceania as a food source (HEAR, 2020). It is reported from Hawaii since the early 1900’s (Wilson, 2002), and is currently present on the islands of Kaua'i, O’ahu, Moloka'i, Lāna'i, Maui and Hawai'i (Vernon and Ranker, 2013). It is available from nurseries and local markets (Badola, 2010). The species is also used as an ornamental, which is likely the means of introduction into the continental USA around the 1930’s (Diddell, 1948). D. esculentum has escaped from cultivation in Florida, Louisiana and Hawaii (Flora of North America Editorial Committee, 2020; HEAR, 2020), facilitated by its air-borne spores (HEAR, 2020).

Soil drainage

• free
• impeded

Soil reaction

• acid
• alkaline
• neutral

Soil texture

• medium

Special soil tolerances

• infertile

Natural Dispersal

Diplazium esculentum spores are dispersed by air. Water is also a possible vector, as it grows near waterways in moist or wet soils (HEAR, 2020).

Vector Transmission (Biotic)

Although there is no specific evidence, it is possible the spores of D. esculentum are dispersed in mud adhered to animals (HEAR, 2020).

Accidental Introduction

 Diplazium esculentum spreads from where it is cultivated into nearby areas (PIER, 2020). Although the leaves are sold in local markets there is no evidence of contamination of other products (HEAR, 2020).

Intentional Introduction

Diplazium esculentum is used as an ornamental and is sold online and in and nurseries worldwide (Huttleston, 1962; Badola, 2010; PIER, 2020).

Diplazium esculentum is listed as a weed of rubber plantations, but no further details are given on the impact it has on this crop (HEAR, 2020).

Diplazium esculentum is an invasive weed of open areas, capable of colonising riverbanks and spreading at a rate of 1 m per year (Flora of New Zealand, 2020). Although no details are available on the precise impact D. esculentum has on biodiversity, it can forms dense thickets and compete with native species for resources (HEAR, 2020).

Sarkar et al. (2018) report that the species might induce male infertility.

• Proved invasive outside its native range
• Has a broad native range
• Tolerant of shade
• Long lived
• Fast growing
• Has high reproductive potential
• Gregarious
• Reproduces asexually

• Monoculture formation
• Negatively impacts human health

• Competition - monopolizing resources
• Rapid growth

• Highly likely to be transported internationally deliberately

Economic Value

The leaves of D. esculentum are sold at local markets throughout Asia and the Pacific (Badola, 2010; Ghorbani et al., 2012; HEAR, 2020; Useful Tropical Plants, 2020). It is particularly significant as an income source for some local communities in the Himalayas (Badola, 2010; Sarkar et al., 2018). Most of its use as a vegetable is from plants harvested from the wild (Badola, 2010; Useful Tropical Plants, 2020).

Diplazium esculentum is also used as an ornamental with plants and spores sold online and in local nurseries (Huttleston, 1962; Badola, 2010).

Social Benefit

Diplazium esculentum is considered the most important edible fern worldwide, being rich in iron, phosphorus, potassium and proteins (Useful Tropical Plants, 2020). Its use as a vegetable is especially popular in Asia and Oceania, and it is widely used in the Himalayas (Badola, 2010; Chawla et al., 2015).

Some traditional medicinal uses reported for D. esculentum are to treat fever, dermatitis, measles, headaches, pains, coughs, wounds, dysentery, glandular swellings, toothaches and diarrhoea (Nwosu, 2002; Badola, 2010; Chawla et al., 2015; Dash et al., 2017). The species is reported to have laxative, anti-inflammatory, antioxidant, anthelmintic, analgesic, antimicrobial and cytotoxic activities (Badola, 2010; Dash et al., 2017). Norhayati et al. (2013) found D. esculentum extracts exhibited in vitro anti-trypanosomal activity. A tonic from the leaves is used for difficult childbirths and the leaves are given to the elderly to maintain their health (Nwosu, 2002; Dash et al., 2017; Useful Tropical Plants, 2020).

The dried rhizomes are used as an insecticide and the leaves as green manure and as cattle bedding (Gaur and Bhatt, 1994; Badola, 2010).