Thelypteris opulenta
(jewelled maiden fern)

Preferred Scientific Name

• Thelypteris opulenta (Kaulf.) Fosberg

Preferred Common Name

• jewelled maiden fern

Other Scientific Names

• Amblovenatum opulentum J.P. Roux
• Amphineuron opulentum (Kaulf.) Holttum
• Aspidium extensum Blume
• Aspidium extensum Fée
• Aspidium opulentum Kaulf.
• Cyclosorus extensus (Blume) H. Itô
• Cyclosorus opulentus (Kaulf.) Nakaike
• Dryopteris extensa (Blume) Kuntze
• Thelypteris extensa (Blume) C.V. Morton

International Common Names

• Spanish: helecho jade; helechos
• Chinese: xian mai mao jue

Local Common Names

• Mexico: helecho palmita

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Pteridophyta
•             Class: Filicopsida
•                 Family: Thelypteridaceae
•                     Genus: Thelypteris
•                         Species: Thelypteris opulenta

Thelypteridaceae is a family of ferns with a cosmopolitan distribution and high species richness. Depending on its circumscription, the number of genera in this family varies from one to approximately 30 and the number of species from 900 to 1000, most of which occur in tropical and subtropical regions of the world (Smith and Cranfill, 2002). In some circumscriptions, Thelypteris constitutes the only genus in the family, containing about 900 species divided into approximately 30 subgenera and/or sections. However, other circumscriptions recognize these subgenera/sections as 30 genera in their own right (Holttum, 1982; Smith, 1992).

The taxonomic status of the species Thelypteris opulenta is still uncertain. For some authors, the species T. opulenta belongs to the genus Cyclosorus and the accepted name is listed as Cyclosorus opulentus. However, for other authors, this species is a synonym of Amblovenatum opulentum (Smith, 1992; Labiak and Prado, 2007; Lindsay and Middleton, 2012; Flora of China Editorial Committee, 2017).

The following description is from the Flora of China Editorial Committee (2017):

Plants 60-100 cm tall. Rhizomes shortly creeping, apices and bases of stipes with dark brown linear-lanceolate scales. Fronds approximate; stipes ca. 30 cm, brownish; laminae 30-60 x 20-30 cm, bases not narrowed or slightly so, apices caudate; pinnae 10-20 pairs, almost sessile; proximal pair of pinnae slightly shortened; middle pinnae linear-lanceolate, 15-25 x 1-2 cm, bases rounded-truncate (or slightly cuneate on proximal pinnae), lobed 1/2-2/3 toward costae, apices long acuminate; segments 25-40 pairs, middle ones subfalcate, 4-8 x 2-3 mm, entire, subacute to obtuse at apices; veinlets 8-10 pairs, proximal pair anastomosing or only connivent, sometimes next vein running to sinus membrane. Laminae herbaceous, yellowish green when dried, with several acicular hairs along veins on both surfaces, minute hairs and many minute yellow spherical glands along veins abaxially, also minute hairs between veins abaxially. Sori orbicular, submarginal, usually sterile on proximal one or two pairs of veins; indusia glabrous or glandular along margins. Sporangia bearing golden spherical glands on stalks. Spores cristate.

T. opulenta was intentionally introduced into new areas as an ornamental and as a houseplant. In Peru, where this species is naturalized and extremely common, the oldest herbarium collection is dated from 1956 (Smith, 1992). In Trinidad, T. opulenta appears in herbarium collections dated from 1966 and the species is currently spreading across the island (Baksh-Comeau, 2000). In Puerto Rico, it is part of a herbarium collection from Naguabo dated 1993 (US National Herbarium). By the year 2000, Liogier and Martorell (2000) listed this species as “recently collected” in the rain forest of Luquillo in Puerto Rico.

Soil drainage

• free

Soil reaction

• acid
• neutral

Soil texture

• heavy
• light
• medium

T. opulenta spreads via spores as well as vegetatively via underground stems (i.e. rhizomes) and often via fleshy underground tubers. Spores are primarily dispersed by wind and water, while rhizomes and tubers are most often dispersed to new areas in dumped garden waste (Smith, 1992; Smith, 1995; Lindsay and Middleton, 2012; Flora of China Editorial Committee, 2017).

Under suitable conditions, T. opulenta forms dense stands with the potential to displace native plant species and alter successional patterns in disturbed areas (Smith, 1995; Aponte, 2012; Oviedo Prieto et al., 2012).

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Tolerant of shade
• Highly mobile locally
• Long lived
• Fast growing
• Has high reproductive potential
• Gregarious
• Reproduces asexually

• Ecosystem change/ habitat alteration
• Modification of successional patterns
• Monoculture formation
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition - smothering
• Rapid growth
• Rooting

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field

T. opulenta is commercialized and cultivated as an ornamental and as a houseplant (Smith, 1995; Flora of China Editorial Committee, 2017).