- Protologue: Hist. Nat. Gen. 4: 70 (1803).
- Family: Polypodiaceae
- Chromosome number: x= 37; P. lingua, P. nummulariifolia, P. piloselloides: 2n= 74; P. lanceolata: 2n= 74, ca. 144, 216
Major species and synonyms
- Pyrrosia lanceolata (L.) Farwell, Amer. Midl. Natur. 12: 245 (1930), synonyms: Cyclophorus adnascens (Swartz) Desv. (1811), Cyclophorus lanceolatus (L.) Alston (1931), P. adnascens (Swartz) Ching (1935).
- Pyrrosia lingua (Thunb.) Farwell, Amer. Midl. Natur. 12: 302 (1931), synonyms: Cyclophorus lingua (Thunb.) Desv. (1827), Pyrrosia heteractis (Thunb.) Ching (1935), P. caudifrons Ching, Boufford & K.H. Shing (1983).
- Pyrrosia longifolia (Burm.f.) C.V. Morton, J. Wash. Acad. Sci. 36: 168 (1946), synonyms: Polypodium acrostichoides G. Forster (1786), Cyclophorus acrostichoides (G. Forster) C. Presl (1851), Pyrrosia acrostichoides (G. Forster) Ching (1935).
- Pyrrosia nummulariifolia (Swartz) Ching, Bull. Chin. Bot. Soc. 1: 52 (1935), synonyms: Niphobolus nummularifolius (Swartz) J. Smith (1841), Cyclophorus nummularifolius (Swartz) C. Chr. (1906).
- Pyrrosia piloselloides (L.) M.G. Price, Kalikasan 3: 176 (1974), synonyms: Drymoglossum piloselloides (L.) C. Presl (1836), Drymoglossum heterophyllum auct. non (L.) Trimen (1887).
P. lanceolata :
- Indonesia: paku tamaga (Javanese)
- Malaysia: kapal (Sandakan), tetumpang (Perak), sakat batu
- Philippines: humang anapatpat, holog, apatpat an dodologapdi (Luzon)
- Papua New Guinea: ilofilifeh, tarawalla, rumbaro
- Laos: ueang pae
- Thailand: tjakweikjon (Karieng), phak peek kai (Chiang Rai).
P. lingua :
- Japanese felt fern (En)
- Thailand: thao hin (north-eastern)
- Vietnam: cây thạch vẽ, kim tinh thảo.
P. longifolia :
- Indonesia: kadaka (Sundanese), paku waceh (Prapat, Sumatra), sungwengto (Halmahera)
- Malaysia: soloio, suloi (Sakai), janglu (Batek)
- Papua New Guinea: tobonallingu, bunu, momabo
- Thailand: samong (Malay-Yala).
P. nummulariifolia :
- Indonesia: picisan (Javanese), paku duduitan (Sundanese)
- Malaysia: paku berenas jantan.
P. piloselloides :
- Dragon's-scale fern (En)
- Indonesia: sisik naga (general), pakis duwitan (Javanese), sakat ribu-ribu (Sumatra western coast)
- Malaysia: picisan, sisik naga
- Philippines: pagong-pagongan.
Origin and geographic distribution
Pyrrosia extends from central Africa through South and East Asia to Oceania (Henderson Island) and New Zealand, but is absent from Hawaii and western and central Australia. The highest diversity is found in the eastern Himalaya and in Sumatra with 12 species each. P. lanceolata is the most widespread species, extending towards Africa and far into the Pacific. P. lingua is a more northern species, found from Korea through Indo-China and Thailand to Nepal and northern India. It is the most frequently cultivated species outside its natural area of distribution, e.g. in the United States. P. longifolia is found throughout South-East Asia, extending to Australia and the Pacific. P. nummulariifolia ranges from the Himalayas, through continental South-East Asia to the Philippines, Borneo, Sumatra, Java, Lesser Sunda Islands and Sulawesi. P. piloselloides extends from north-eastern India throughout South-East Asia.
Pyrrosia species are mainly used medicinally and some are also used as an ornamental. Most species listed here have succulent leaves (only the leaves of P. lingua are leathery), the juice of which is applied locally for various purposes. The juice of P. lanceolata is used in Malaysia against dysentery and mixed with seeds of Nigella sativa L. ("jintan hitam") and onion, it is applied externally against headache. In the Pacific, leaves are used as a poultice on wounds. The juice of P. longifolia is applied in labour. The juice of P. nummulariifolia is administered internally against cough and stomach pains. P. piloselloides is used internally against cough, dysentery and gonorrhoea; it is chewed as a remedy against purulent inflammation of the gums and tooth sockets, often leading to loosening of the teeth (pyorrhoea). Externally, it is used in the Philippines as a styptic for coagulating blood of capillary haemorrhagesand for eczema. P. lingua is the best known Pyrrosia species cultivated as an ornamental and is grown in pots and baskets or as ground cover. Antiviral activity has been detected in P. lingua . In China and Japan, a decoction of P. lingua has been known for thousands of years as a diuretic for treatment of various disorders of the urinary tract. Together with P. petiolosa (H. Christ) Ching it is sold as the Korean crude drug "suk wi". Leaves of Pyrrosia species constitute the Chinese medicine "shi-wei", or "Folium Pyrrosiae". P. sheareri (Baker) Ching, found in China, is used on a large scale to treat bacillary dysentery.
Production and international trade
The species of Pyrrosia mentioned are not available commercially but they are fairly widespread in cultivation in fern collections and spores are listed in several spore banks. Dried leaves collected for herbal medicines are traded locally.
P. lanceolata and P. piloselloides contain alkaloids, arbutin, amygdalin, tannin, saponin, formic acid, oxalic acid and tartaric acid. Several other compounds have been isolated from some Chinese species of Pyrrosia , among which mangiferin, isomangiferin, sucrose, β-sitosterol and diploptene, the concentrations varying per species.
Extracts of P. lingua show a moderate inhibition of the angiotensin-inverting enzyme (ACE) which plays a role in the build up of high blood pressure. The methanolic extract has a moderate inhibiting effect on xanthine oxidase which catalyzes in the conversion of hypoxanthine via xanthine to uric acid, which plays a crucial role in gout. The herb was found highly effective against type 1 herpes simplex virus. In clinical tests, among the 78 cases of herpetic keratitis due to HSV1 treated by aqueous extracts of P. lingua and Prunella vulgaris L. in eye drops, 38 were cured, 37 improved and 3 showed no benefit.
Isolated from P. lingua were: five hopane derivatives (22,28-epoxyhopane, 22,28-epoxyhopan-30-ol, hopane-22,30-diol, hop-22(29)-en-30-ol and hop-22(29)-en-28-ol) and the dammarane triterpenoids: octanordammarane, (18S)-18-hydroxydammar-21-ene, (18S)-pyrrosialactone, (18S)-pyrrosialactol, 3-deoxyocotillol, and dammara-18(28),21-21-diene. Furthermore cyclohopenol and cyclohopanediol, two hexacyclic hopane derivatives, (28S)-28,29-cyclohop-22(30)-en-28-ol and (22R,28S)-28,29-cyclohopane-22,28-diol, along with hop-22(29)-en-28-al were isolated from the rhizomes. The major compounds found in the essential oil are hexanal, vanillin, 4-hexen-1-ol, 1-hepten-3-ol, and 3-hydroxy-2,2,4-trimethylpentyl-isobutyrate. The oil has a greenish and fatty acid-like odour.
P. serpens (Forster) Ching, found in Oceania, predominantly accumulates naringenin and eriodictyol-7-neohesperidosides. A range of apigenin and luteolin O- and C-glycosides are also accumulated together with the flavonol glycoside kaempferol-3-sophoroside-7-α-L-arabinofuranoside.
Mainly epiphytic ferns. Rhizome creeping, branched, mostly growing exposed on top of the substrate, covered with peltate scales, dorsally bearing leaves at intervals of 1-7 cm. Leaves simple, petiolate, articulated to the rootstock, mono- or dimorphic, often succulent, covered with stellate hairs. Sterile leaves (if present) shorter and wider than the fertile ones. Sori naked, round, elongate or forming a longitudinal coenosorus along the margin of the lamina.
- P. lanceolata . Small, glossy green, thin-fleshy fern, clambering over tree trunks and rocks by its slender creeping rhizome. Rhizome 1-2 mm thick, wiry. Scales up to 3 mm long, appressed, dark, with a dentate, scarious margin. Leaves dimorphic; sterile leaves ovate-elliptical to narrowly ovate, 2-12 cm × 0.4-2 cm; fertile leaves linear, 3.5-29 cm × 0.3-1.3 cm, the apical fertile part often distinctly narrower than the sterile basal part; stellate hairs monomorphic, with appressed, straight rays only, forming a sparse to dense, thin cover on the undersides of the leaves. Sori circular, 0.5-1 mm across, with a tuft of stellate hairs in the centre, in several rows between midrib and margin.
- P. lingua . Full-foliaged looking fern with a slender, creeping, amply branching rhizome 1.2-3.7 mm thick. Scales up to 9.5 mm long, lustrous light brown, with curly marginal or superficial cilia. Fertile leaves with the petiole 1.5-25 cm long, lamina ovate-elliptic to narrowly ovate-elliptic, 5-25 cm × 0.8-5 cm, the apex rounded to acuminate, occasionally apiculate; sterile leaves wider, up to 7.2 cm broad; stellate hairs mono- or dimorphic, persistent. Sori circular, 0.5-2 mm across, approximate, often confluent along the veins.
- P. longifolia . Fern with very thick-fleshy, long narrow leaves. Rhizome 1.8-2.7 mm thick, often rather brittle. Scales elliptical, up to 1.5 mm long, appressed, dark with an entire, scarious margin, rather resembling scale insects. All leaves similar, strap-shaped, 20-100 cm × 0.5-4.5 cm, occasionally longer; stellate hairs monomorphic, with appressed, straight rays only, forming a mostly rather sparse, thin cover on the underside of the leaves. Sori circular, 0.5-1 mm across, with a tuft of stellate hairs in the centre, in several rows between midrib and margin.
- P. nummulariifolia . Small, wide-creeping fern with fleshy leaves. Rhizome filiform or wiry, 0.6-1.6 mm thick. Scales up to 5.7 mm long, brown, margin ciliate in the upper part. Leaves dimorphic; sterile leaves sessile or with petioles up to 2.5 cm, lamina round to elliptical, 0.8-5 cm × 0.6-2 cm; fertile leaves with petiole up to 2.5 mm long, lamina elliptical to linear, 1.5-12.5 cm × 0.3-1 cm; stellate hairs dimorphic, hairs with mainly straight, acicular rays separated from a dense layer of hairs with mainly crisped rays, together forming a thick cover especially on the undersides of the leaves. Sori round, 1-1.5 mm across, mostly hidden in the stellate hairs.
- P. piloselloides . Small fern with thick fleshy, glossy green leaves and a wide-creeping rhizome. Rhizome filiform, up to 1 mm thick. Scales roundish-ovate, up to 1 mm long, dark in the centre with a dentate-ciliate scarious margin. Leaves dimorphic; sterile leaves sessile or short-petiolate, often appressed to the substrate, lamina round to elliptical, 1-7 cm × 1-2 cm; fertile leaves with petiole to 0.5 cm long, lamina linear, 4-16 cm × 0.3-1.5 cm; stellate hairs monomorphic, all with acicular rays, forming a sparse, appressed layer. Sori linear, running along the margin of the leaf.
Growth and development
The gametophyte of Pyrrosia is cordate, with a thin median midrib and a glandular margin. Archegonia and antheridia are formed on the same prothallus. In some species the prothalli may pass through a stage during which they are elongated and relatively narrow and only bear antheridia. Most Pyrrosia species are slow growers.
Other botanical information
Pyrrosia comprises about 50 species, including those formerly referred to as Drymoglossum C. Presl and Saxiglossum Ching. Characteristic of Pyrrosia are the peculiar stellate hairs, a sclerenchyma sheath in the rhizome and the absence of pinnate divisions of the leaves. P. lanceolata is very variable; the description given hereapplies to the form usually identified as P. adnascens , which is the most common form at low altitudes in South-East Asia. Other forms of P. lanceolata vary mainly in the shape and size of the sterile leaves and the degree of leaf-dimorphism. In South-East Asia the names P. nuda (Giesenh.) Ching and P. varia (Kaulf.) Farw. refer to such forms. In P. lingua , two varieties are distinguished: var. heteractis Hovenkamp: indumentum dimorphic, a dense persistent mat of whitish to greyish-brown hairs in an upper layer with boot-shaped rays and a lower layer with mainly woolly rays; some authors consider this taxon as a separate species; and var. lingua : indumentum monomorphic, a thin mat of persistent, light to greyish-brown hairs with boot-shaped rays. Small forms of P. lingua are often misidentified as P. petiolosa . P. lingua is a popular ornamental fern because it is attractive and easy to grow, tolerating irregular watering and surviving moderately low temperatures. In cultivation the leaves may reach 50 cm length. Numerous cultivars have been developed, mostly differing in their peculiar leaf forms, e.g. "Cristata" (crested tongue fern with the leaf tips several times irregularly forked) and "Monstrifera" (lacerate pyrrosia because the leaf margins have irregular fringe-like lacerations). Contrary to Linnaeus, a number of authors have confused P. piloselloides with or considered it conspecific with P. heterophylla (L.) M. Price, a closely similar species restricted to southern India, Sri Lanka and the Seychelles. All references to P. heterophylla or its synonyms for South-East Asia should be taken as referring to P. piloselloides . P. piloselloides has also been confused with P. nummulariifolia , from which it can easily be distinguished by its short, appressed, dentate scales on the rhizome and the much sparser cover of hairs on the leaves. The epithet nummulariifolia is often written as nummularifolia , following the original spelling by Swartz. However, this is a compound form derived from nummularia and folius , and as such the form without the second (connecting) – i should be treated as an error to be corrected.
All Pyrrosia species are fairly common, often rather hardy epiphytes throughout the South-East Asian tropical lowlands. P. lanceolata is common on all kinds of sites, mostly at low altitudes, but sometimes up to 1500 m altitude. P. lingua grows as an epiphytic and epilithic, and sometimes as a terrestrial, in sheltered to exposed sites, from sea-level up to 3000 m altitude. It can tolerate some frost. P. longifolia is a common epiphyte, frequent in exposed locations, often in the littoral zone, at low altitudes. P. nummulariifolia is often found as an epilithic, on limestone. As an epiphyte, it often grows in the crown of trees. P. piloselloides is often found colonizing bare bark on tree trunks and can cover entire trees, including the thin twigs. It grows from sea-level up to 1000 m altitude. Its gametophyte is able to tolerate up to 50 days of drought. Upon rehydration, the cells recovering from water stress are capable of forming new gametophytes.
Propagation and planting
All Pyrrosia species are easily propagated by rhizome cuttings and by layering. Rhizome segments to be transplanted should contain at least one actively-growing apex and should be firmly fixed to a moist substrate until the plant is established.
Pyrrosia species are not cultivated commercially on a large scale. The species described here can be easily maintained in gardens or greenhouses under conditions resembling their natural habitats. P. lingua is a slow grower. P. piloselloides is potentially a pest in plantations and could easily be grown and harvested in large quantities.
Genetic resources and breeding
Germplasm collections or breeding programmes are not known to exist for Pyrrosia . None of the used species are rare or in danger of genetic erosion.
The available evidence suggests that several Pyrrosia species contain useful active compounds with coagulant, laxative or antiviral properties. More research is needed to discover the best sources for special medicinal preparations.
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