Osmunda japonica

 

Bmily:otanical Name : Osmunda japonica
Family:  Osmundaceae
Genus: Osmunda
Section:Euosmunda
Species:O. japonica
Kingdom: Plantae
Division: Pteridophyta
Class: Polypodiopsida /Pteridopsida (disputed)
Order: Osmundales

Synonyms: Osmunda nipponica Makino

Common Name : Japanese royal fern or Japanese flowering fern ,Zenmai (In some parts of China it is called juecai in Mandarin), Tibet and Japan it is called zenmai in Japanese.

Habitat :Osmunda japonica is native to E. Asia – China, Japan. It grows in moist places all over Japan.

Description:
Osmunda japonica is a deciduous herbaceous plant which produces separate fertile and sterile fronds. The sterile fronds are spreading, up to 80-100 cm tall, bipinnate, with pinnae 20-30 cm long and pinnules 4-6 cm long and 1.5-2 cm broad; the fertile fronds are erect and shorter, 20-50 cm tall.

It grows in moist woodlands and can tolerate open sunlight only if in very wet soil. Like other ferns, it has no flowers, but rather elaborate sporangia, that very superficially might suggest a flower, from which the alternative name derives.

Like its relative Osmundastrum cinnamomeum (Cinnamon fern), the fertile fronds become brown-colored and contain spores. The sterile (vegetative) fronds resemble in form, another relative, Osmunda regalis (Royal fern).

CLICK & SEE  THE  PICTURES

Rhizome: erect, massive, forming a trunk, occasionally branching, hairs and old stipe bases woven together with black, fibrous roots.

Frond: 50 cm high by 40 cm wide, deciduous, dimorphic, fertile fronds earlier, erect, sterile later, arching, blade/stipe ratio: 5:4 for sterile fronds, 1:1 for fertile fronds.

Stipe: stipules (flared leaf base), unique to the family/genus, pale reddish brown, long lax hairs, but soon glabrous, vascular bundles: 1 in a U-shape where the top of the arms continue to curl.

Blade: 2-pinnate, sterile oblong, widest at the bottom, fertile consisting entirely of sporagia, papery, reddish to light brown hairs, soon falling.

Pinnae: 4 to 6 pair, catadromous; pinnules oblong, to 10 cm; margins minutely dentate; veins free, forked.

Sori: none, indusium: absent, sporangia: large, globose, tan or black when mature, spores green.
Cultivation:
Likes a soil of swamp mud and loamy or fibrous peat, sand and loam. Succeeds in most moist soils, preferring acid conditions. Requires a constant supply of water, doing well by ponds, streams etc. Plants thrive in full sun so long as there is no shortage of moisture in the soil and also in shady situations beneath shrubs etc. Plants are hardy to at least -20°c, they are evergreen in warm winter areas but deciduous elsewhere. Members of this genus are rarely if ever troubled by browsing deer. Closely related to O. regalis.

Propagation :
Spores – they very quickly lose their viability (within 3 days) and are best sown as soon as they are ripe on the surface of a humus-rich sterilized soil in a lightly shaded place in a greenhouse. Keep the compost moist, preferably by putting a plastic bag over the pot. Plants develop very rapidly, pot on small clumps of plantlets as soon as they are large enough to handle and keep humid until they are well established. Do not plant outside until the ferns are at least 2 years old. Cultivars usually come true to type[200]. Division of the rootstock in the dormant season. This is a very strenuous exercise due to the mass of wiry roots

Edible Uses: the young frond of Osmunda japonica is used as a vegetable.

Medicinal  Uses: Not yet known.

Known Hazards: Although no reports of toxicity is yet found for this species, a number of ferns contain carcinogens so some caution is advisable. Many ferns also contain thiaminase, an enzyme that robs the body of its vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.
Resources:
https://en.wikipedia.org/wiki/Osmunda_japonica
http://hardyfernlibrary.com/ferns/listSpecies.cfm?Auto=117
http://www.pfaf.org/user/Plant.aspx?LatinName=Osmunda+japonica

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