Drynaria (Bory) J. Smith
- Protologue: J. Bot. (Hooker) 3: 397 (1841).
- Family: Polypodiaceae
- Chromosome number: x= 36, 37;D. quercifolia,D. rigidula,D. sparsisora: 2n= 74
Major species and synonyms
- Drynaria fortunei (Kunze ex Mett.) J. Smith, in Seeman, Bot. voy. herald: 425 (1857), synonym: Polypodium fortunei Kunze ex Mett.(1857).
- Drynaria pleuridioides (Mett.) Diels, Nat. Pflanzenfam. 1(4): 330 (1899), synonym: Polypodium pleuridioides Mett. (1866).
- Drynaria quercifolia (L.) J. Smith in J. Bot. (Hooker) 3: 398 (1841), synonym: Polypodium quercifolium L. (1753).
- Drynaria rigidula (Swartz) Bedd., Ferns Brit. Ind.: t. 314 (1869), synonyms: Polypodium rigidulum Swartz (1801), D. diversifolia (R. Br.) J. Smith (1841).
- Drynaria sparsisora (Desv.) T. Moore, Index fil.: 348 (1862), synonyms: Polypodium sparsisorum Desv. (1811), D. linnei (Bory) Bedd.(1869).
- D. fortunei .
- Northern Indo-China: hou sen chan (monkey's gingler).
- D. pleuridioides
- Indonesia: tameti (Alor).
- D. quercifolia
- Oak-leaf fern (En)
- Indonesia: daun kepala tupai
- Malaysia: daun kepala tupai, sakat laipang
- Philippines: pakpak-lauin (Tagalog), paipai-amo, kabkab (Bisaya). Burma (Myanmar): thil-ka-sen (Wakema), kyaukpyu (Ramree Island)
- Thailand: kratae tai mai (central), kra prok waao (Prachuap Khiri Khan, Prachin Buri), kuut khae hok (Karen, Mae Hong Son).
- D. rigidula
- Basket fern (En)
- Indonesia: paku kayakas (Sundanese), simbar layangan (Javanese), pasilan kelapa (Java, meaning medicinal rhizome on stem of coconut tree). New Guinea: poto (Southern Highlands), tjekee (Irian Jaya)
- Philippines: pinog yupar (Luzon)
- Thailand: kra prok lek (Chanthaburi), kuut tang, kuut mai (northern).
- D. sparsisora :
- Indonesia: paku langlayangan (Sundanese), barang-barang (Makassar), lilianga (Ternate)
- Malaysia: kakayan (Sarawak). New Guinea: talwala (Sepik), kangkoms (Irian Jaya)
- Philippines: kabkab (Palawan), apatpat di batu (Luzon), glemu (Mindanao)
- Thailand: kuut hok (northern), phang-ngaa (peninsular), wean ngun kwak (peninsular).
Origin and geographic distribution
Drynaria is an Old World fern genus and is found from Africa, throughout Asia to north-eastern Australia and comprises about 15 species (about 10 in South-East Asia). The greatest diversity is found in continental Asia, especially in China. D. fortunei occurs in Thailand, Indo-China, southern China and Taiwan. D. pleuridioides is only known from Indonesia (Sumatra, Java, Lesser Sunda Islands, Sulawesi and the Moluccas). D. quercifolia is distributed from India and southern China (Hainan), throughout South-East Asia to tropical Australia and Polynesia. In South-East Asia it is one of the most common epiphytic ferns, found in the crowns of forest trees but often also on roadside and village trees. D. rigidula occurs in Burma (Myanmar), Thailand, Indo-China, China (Hainan), Malaysia, Indonesia, the Philippines, New Guinea, Australia and Polynesia. D. sparsisora is found from Sri Lanka, throughout South-East Asia to southern China, tropical Australia and Polynesia.
Most species of Drynaria are quite often grown as ornamentals and certainly all have ornamental value. Some are also used medicinally or as a stimulant and as a vegetable. D. fortunei is used in Chinese medicine to tonify deficient kidneys manifested as lower back pain and with weakness of the legs, to invigorate blood, to stop bleeding and to heal wounds. In Alor (Indonesia) roots of D. pleuridioides are used as a substitute for Areca nut (betel) and it is believed that its leaves, placed on a bamboo pole near Areca trees, curse thieves with insanity. In Peninsular Malaysia, the leaves of D. quercifolia are pounded and applied as a poultice to swellings; the diluted juice is sprinkled over the head of a patient to treat fever. In the Philippines, aside from being an ornamental, it is a medicine for stomach ache, fever, coughs and a dilute decoction of the rhizomes is astringent, helpful for haemoptysis and if made more concentrated, it can be used as an anthelmintic. In Sumba (Indonesia), inner tissues from the rhizome are mixed with gum (from the tree Lannea coromandelica (Houtt.) Merr., "kaju santen") to make a poultice that is applied to the head against headache. In India, this plant is used for strong fever, cough, and phthisis. To comfort an aching stomach, the stem is cut into fine pieces, soaked in water and the extract is drunk. In Sulawesi (Indonesia), leaves of D. rigidula are eaten as a vegetable. In Java (Indonesia) the juicy rhizomes are collected by medicine men, but only when they are growing on the coconut tree. As in the Philippines, a decoction of the rhizome is used to cure gonorrhoea and dysentery. Inhabitants of the Treasury Islands used it as a remedy for seasickness and they believed that chewing certain parts of the plant made warriors agile and light-footed. In Indonesia, roots of D. sparsisora (like those of D. pleuridioides ) may be used as a substitute for Areca nut. Sap of the rhizome mixed with other plant parts has been considered beneficial for persistent diarrhoea. The bruised rhizome is used externally to reduce swollen limbs and to mature boils. A decoction of the rhizome mixed with Inocarpus fagiferus (Parkinson) Fosberg is applied to treat virulent gonorrhoea. The leaves mixed with honey and Alpinia galanga (L.) Willd. may be administered into the nose as a treatment against vomiting. It is also used as a medicine for the eyes and in the Philippines the roots are applied against snake bites. In Indonesia, children use the base leaves as kites and in Makassar young foliage leaves are eaten as a vegetable. In India the rhizome paste of Drynaria is applied to induce labour and easy childbirth; in diluted form it is used to treat ear infections.
In China, D. sinica Diels (syn. D. baronii (H. Christ) Diels)("gusuibu") rhizome is used with Psoralea fruit ("buguzhi"), Cyathula root ("niuxi") and walnut seed ("hutaoren") for lower back pain and weakness of the legs. It can also be used with prepared Rehmannia root ("shudihuang") and dogwood fruit ("shanzhuyu") for tinnitus, deafness and toothache. Drynaria is used with magic ingredients and myrrh ("moyao") for swellings and pain due to external trauma or injury. As one of the constituents of "kwat sui po" it is applied as an antibiotic and tonic against pain in the kidney and broken limbs.
Production and international trade
There is hardly any information on production and international trade available for Drynaria although most species are also cultivated as ornamentals. In early 2001, the price of a 10% extract (probably of D. fortunei ) on the wholesale market amounted to US$ 38 per kg and US$ 10 per 100 g for the rhizome extract, and US$ 7 per pound of the powder "gusuibu".
Allegedly, Drynaria enhances the calcium absorption of bone, increases blood calcium and inorganic phosphorus levels; it lowers blood lipid levels and has an antibiotic activity due to streptomycin. Administration of 100-150 g of the fresh plant per day can result in, e.g. acute toxic reaction with dry mouth, polyogia, palpitation, chest distress, vagueness and platycoria. Through tissue culture and isotope tracing, it has been found that injection of gusuibu ( D. sinica ) significantly promoted calcification of the cultivated chicken embryo bone primordium, increased ALP activity in the cultivated tissue, and accelerated synthesis of proteoglycan. Proteoglycan synthesis was an important factor in the promotion of calcification. The rhizomes of D. sinica contain propinqualin ((-)-epiafzelechin-3-O-β-D-allopyranoside), 4-O-β-D-glucopyranosyl caffeic acid, and β-sitosterol-3-O-β-D-glucopyranoside.
In the Philippines D. quercifolia contained alkaloids (rhizome, leaf), tannin (leaf), saponin (leaf), oxalic and formic acids (leaf), D. rigidula arbutin (rhizome), amygdalin (rhizome), and in all parts formic, oxalic and tartaric acids ranging from detectable to large amounts. A crude extract from the rhizome of D. quercifolia has antibacterial properties. In culture, it is effective in inhibiting the growth of the bacteria Klebsiella pneumoniae which is assocated with pneumonia in humans.
Epiphytic, epilithic or rarely terrestrial ferns with the rhizome concealed by non-green, pinnatifid base leaves (so-called nest leaves) behind which green foliage leaves rise up. Rhizome creeping, branched, densely scaly; scales peltately attached or basifixed, the margins toothed or shortly hairy, apex with a distinct glandular top-cell, spreading or appressed; phyllopodia absent, rhachises often persisting. Leaves dimorphic with shallowly lobed base leaves (nest leaves) and large, deeply lobed foliage leaves; base leaves sessile, lamina rounded to ovate or elliptical, entire to lobate-pinnatifid, initially green but becoming brown and papery, with trichomes, glands and scattered scales, persisting for a long time, acting as humus collectors; foliage leaves green, sessile or with an often winged petiole, lamina pinnatifid, sometimes pinnate, with trichomes, glands and scattered scales, especially around the rachis and costae; pinnae equally wide throughout or with a basal constriction, base adnate, margins serrate, apex acute, apical pinna often aborted; venation reticulate, with very few free included veinlets; nectaries present on the foliage leaves but only active in very young ones, in species with pinnatifid leaves appearing as large translucent spots near the junction of the primary veins and the midrib, in species with pinnate leaves occurring on the stalks of the pinnae. Sori round, borne at the angles of the small areoles of the foliage-leaves, exindusiate. Spores monolete, ellipsoid to reniform, 37-77 μm in diameter, pale or pigmented, surface echinate or tuberculate.
- D. fortunei . Epiphytic or epilithic fern, rhizome 1-2 cm in diameter, densely rufous scaly. Base leaves rounded, up to 9 cm × 7 cm, lobed, lobes oblong-subdeltoid, up to 1.5 cm wide, brown; foliage leaves with up to 10 cm long, winged petiole, lamina ellipsoid to ovate, up to 45 cm × 20 cm, deeply pinnatifid, lobes narrowly oblong, up to 11 cm × 2.5 cm, margin entire but irregularly waved, midrib and main veins minutely pubescent. Sori dispersed from the upper central portion downwards, 2 rows of round sori or a single row of crescent sori between adjacent main veins. Spores with globular excrescences.
- D. pleuridioides. Epiphytic fern, up to 1.25 m tall, rhizome 1-2 cm in diameter, internodes up to 10 cm long, scales peltate, spreading, 4-8 mm × 1 mm, dentate or curly ciliate. Base leaves overlapping, lobed, 10-30 cm × 7-22 cm, margin irregularly denticulate; foliage leaves with up to 25 cm long, winged petiole; lamina pinnatifid, 40-100 cm × 20-40 cm, pinnae 12-25 cm × 1-3.5 cm, gradually smaller towards apex, margin entire. Sori round, 2-3 mm in diameter, in one row between midrib and margin, distinctly sunken into the leaf surface, sporangia glabrous. Spores verrucate, without spines or globules.
- D. quercifolia . Epiphytic, epilithic or occasionally terrestrial fern, rhizome about 2-3 cm in diameter, woolly because of persistent soft scales; scales gradually narrowing from the peltately attached base to the acute apex, up to 2.5 cm × 1 mm, soft, light brown to black-brown with paler, dentate margin. Base leaves more or less ovate, 10-50 cm × 10-40 cm, shallowly to rather deeply lobed with rounded lobes; petiole of foliage leaves unconspicuously winged, up to 35 cm long, lamina pinnatifid, 40-100(-150) cm × 15-50 cm, upper part often drooping, lobes oblique, 1-25(-30) cm × 2-5 cm, shortly acuminate, separated by narrow sinuses, thin but stiffly leathery with reticulate venation. Sori round, 1-2 mm in diameter, in two almost regular rows between adjacent main lateral veins of the foliage leaves, not or only slightly impressed into the laminal surface, sporangia glabrous. Spores with spines.
- D. rigidula . Epiphytic or terrestrial fern, 0.5-2 m tall, rhizome 1-2 cm in diameter, fleshy, densely scaly; scales narrowed gradually from the peltately attached base to an acute or acuminate apex, 5-13 mm × 0.5-1.5 mm, brown to red-brown, margins pale and ciliate. Base leaves overlapping, ovate, 10-30 cm × 5-15 cm, margin shallowly to deeply lobed, the lobes rounded and finely denticulate; young foliage leaves covered with white, very small scales or stellate hairs; petiole up to 40 cm long, not winged but in upper part bearing small appendages spaced like the pinnae; lamina pinnate, in outline 25-100(-200) cm × 12-50 cm, the pinnae jointed to the rachis, papery to somewhat leathery, with short, winged stalks, each bearing a small gland; pinna strap-shaped, 8-25(-30) cm × 0.5-3 cm, base cuneate, margin crenate to serrate, apex obtuse to acuminate, venation reticulate. Sori round, 1-2 mm in diameter, in a single row on each side of the midrib, one sorus between each pair of the main lateral veins, closer to the midrib than to the margin, sunken into the laminal surface, sporangia glabrous. Spores with spines.
- D. sparsisora . Epiphytic, epilithic or terrestrial fern, rhizome 1-3 cm in diameter, fleshy, densely scaly, smooth and snake-like when old, covered with dark scale bases, the narrow apical portions having broken off; scales peltate, appressed, overlapping, narrowed abruptly above the rounded base, tapering to a narrow, acute, rather spreading apex, 1-11 mm × 1-3 mm, stiff, brown to very dark brown, margins paler and bearing very fine hair-like teeth. Base leaves imbricate, ovate, 10-35 cm × 10-25 cm, margin shallowly or deeply lobed, the lobes rounded; foliage leaves stiffly erect; petiole 5-18 cm long, winged; lamina leathery, deeply pinnatifid, in outline 30-80 cm × 15-30 cm, the lobes strap-like, narrowed slightly towards the base, tapering to a mostly acute apex, 10-30 cm × 1.5-4.5 cm; veins reticulate between prominent main lateral veins. Sori round, 1-2 mm in diameter, in more than two irregular rows between adjacent main lateral veins of the foliage leaves, not or only slightly sunken into the laminal surface; sporangia glabrous. Spores with spines.
Growth and development
When a rhizome of Drynaria is exposed to light it develops base leaves (nest-leaves). When the rhizome is subsequently shaded by the closely appressed base leaves, the dark condition signals the development of the foliage leaves. The base leaves collect litter, which contributes to the nutrition of the plant, and also retain water. When the base leaves disintegrate, some Drynaria species retain the naked rachises for a long time, sometimes with an empty mesh of finer veins. Epiphytic D. rigidula often encircles the trunk of a tree many times (forming a cylinder around the trunk) and may form large nests in the crown. Juvenile leaves of D. rigidula may be variously intermediate between base and foliage leaves; base leaves may be absent in older plants.
Other botanical information
Drynaria is characterized by its peculiar leaf dimorphism with often sessile, smaller, always sterile base leaves and stalked, sterile or fertile foliage leaves with a characteristically aborted apex with a peculiar lopsided look because a lateral pinna has taken its place, the leathery texture of the leaves and the presence of nectaries between the bases of the pinnae. D. quercifolia resembles D. sparsisora but can be distinguished by its woolly rhizome, its usually larger, drooping leaves and its very regular rows of sori. In D. rigidula , "Vidgenii" is a cultivar with long, hanging, dark green leaves with narrowly lobed segments; "Whitei" has leaves with very broad, deeply-lobed segments to impart a ruffled appearance and the crowded segments overlap each other. Characteristic features of D. sparsisora are its snake-like old rhizomes, its erect foliage leaves and its irregularly arranged sori. Without rhizomes, it is almost impossible to distinguish between D. sparsisora and D. quercifolia .
A closely related genus of Drynaria is Aglaomorpha Schott with about 30 species in tropical Asia, of which 14 in Malesia. It can be distinguished from Drynaria by the absence of base leaves and its normally developed apical pinnae. In general they are large to very large epiphytic ferns with thick rhizomes and pinnatifid to pinnate leaves. They are beautiful ornamentals, e.g. Aglaomorpha heraclea (Kunze) Copel. (synonyms: D. heraclea T. Moore, Drynariopsis heraclea Ching) with sessile pinnatifid leaves up to 3.5 m long and Aglaomorpha coronans (Mett.) Copel. (synonyms: D. coronans T. Moore, D. conjugata Baker ex Bedd.) with leaves up to about 2 m long.
D. fortunei grows, often in the shade, on trunks of trees in several types of forest, on rocks and occasionally on brick walls. Its altitudinal range is 0-1300 m. D. pleuridioides grows on trunks of trees, encircling the trunk many times or spirally climbing. It occurs in primary and secondary forest, occasionally in plantations, usually at 500-1500 m altitude. D. quercifolia grows terrestrially among rocks, or as an epiphyte on tree trunks, in open forest, rain forest margins and in dry rain forest, from sea level up to 1200(-1900) m altitude. In South-East Asia D. quercifolia is one of the most common epiphytic ferns, found in the crowns of forest trees but often also on roadside and village trees. In rubber and coconut plantations they sometimes become a troublesome weed. D. rigidula is often found on or among rocks, terrestrially forming a crust, or it grows as an epiphyte on old trees in open forest, on wayside trees and trees in plantations. It grows from sea level up to 2400 m altitude but prefers a cooler climate and is more often found in mountain forest. D. sparsisora normally grows spirally on tree trunks in primary or secondary, open or dry forest, from sea level up to 1700 m altitude. It is found occasionally in sandy soils or on rocks; it tolerates more exposure than D. quercifolia . As litter collector, Drynaria is less efficient than bird's nest ferns ( Asplenium nidus L.) and staghorn ferns ( Platycerium species). The nectaries secrete some fluid and are only active in young leaves. Normally, nectaries attract insects like ants, but their function in ferns is unknown. D. rigidula however, frequently harbours ants.
All species of Drynaria grow from spores, but propagation is easier by rhizome divisions. Most Drynaria species can be grown readily on rocks or trees in tropical gardens or in a large pot or basket with a coarse soil mixture. Once established, plants are very tolerant to drought.
Genetic resources and breeding
The Drynaria species here described are quite common and not threatened by extinction. There are no known germplasm collections or breeding programmes for Drynaria .
Drynaria species are very beautiful and prized ornamentals. Further research is needed to facilitate domestication and commercial cultivation and its trade as an ornamental. The medicinal value of several species deserves further investigation.
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Titien Ngatinem Praptosuwiryo