Tokyoensis is the Latinization of the city in Japan, Tokyo.
Rhizome: short, thick, erect, also branching infrequently, scaly.
Frond: 90 cm high by 20 cm wide, deciduous, monomorphic, blade/stipe ratio: 6:1.
Stipe: grooved, green to purple, adjacent fronds exhibiting a variety of shades, scales lanceolate to long-ovate, abruptly acuminate, to 1.5 cm, membranous, brown, often darker in basal portion, vascular bundles: 3-7 in a c-shaped pattern.
Blade: 1-pinnate, but in some specimens the pinnae pass over the line from lobed to pinnatifid, oblanceolate, widest above the middle, herbaceous to somewhat leathery, scales on rachis lanceolate to linear.
Pinnae: 25 to 35 pair, shallowly lobed to pinnatifid, the lowest pair much reduced; the proximal lobe enlarged, ear-like; veins simple, immersed on top surface.
Sori: round, 1 per lobe of the pinna, medial, indusium: reniform, at a sinus, sporangia: brownish.
Habitat: sunny or half-shaded wetlands.
Distribution: China, Japan, Korea.
Hardy to -25°C, USDA Zone 5.
Among the slenderest, most upright of fronds, the blade stipe ratio also distinctive, and the auricled pinnae.
Nephrodium tokyoense Matsum. ex Makino
Aspidium transitorium Christ
Dryopteris tokyoensis. Habit, early June.
Ray Edwards, © 2004.