Flora-Fauna

Cystopteris fragilis (L.) Bernh.

(Neues J. Bot. 1(2): 26; 1806 – Nouvelle Flore du Liban et de la Syrie, vol. 1, Pl. XXXV nº 3; 1966)

• Life-form & habit: Small, delicate deciduous fern with slender, creeping rhizomes and tufted fronds 10–40 cm long. Rhizome densely covered with pale brown, lanceolate scales. Fronds arising singly or in small clusters, easily broken off at the base (hence fragilis).

• Fronds: Blade ovate-lanceolate, bipinnate to tripinnate; rachis and stipe slender, light green, smooth or sparsely scaly near the base. Pinnae 10–20 pairs, opposite or subopposite, lanceolate, decreasing towards the apex. Pinnules ovate, serrulate, sometimes lobed, with distinct midveins.

• Sori: Numerous, small, round, positioned along the veins near the midrib of each pinnule; indusia thin, translucent, attached at one side, early becoming reflexed or detached. Spores light brown, finely papillate.

• Phenology: Fronds appear in spring and wither by late summer; fertile fronds mature from May to August.

• Habitat & elevation: Moist rock crevices, shaded limestone cliffs, screes, and mountain springs; also along stream banks and damp forest slopes. Occurs from 800 to 2 600 m in Lebanon, often in cool, humid microhabitats protected from direct sun exposure.

• Lebanese distribution: Recorded by Mouterde from high mountains of Mount Lebanon — notably Barouk, Dahr el-Baïdar, and the Sannine–Makmel range; rare but locally abundant near perennial springs and shaded rocks.

• Native to: Afghanistan, Alaska, Albania, Alberta, Algeria, Altay, Amur, Arizona, Austria, Azores, Baleares, Baltic States, Belarus, Belgium, British Columbia, Bulgaria, Buryatiya, California, Cameroon, Canary Is., Cape Provinces, Cape Verde, Central European Russia, Chad, China North-Central, China South-Central, China Southeast, Chita, Colorado, Comoros, Connecticut, Corse, Czechia-Slovakia, Denmark, DR Congo, East European Russia, East Himalaya, Equatorial Guinea, Ethiopia, Finland, France, Free State, Føroyar, Germany, Great Britain, Greece, Greenland, Gulf of Guinea Is., Honduras, Hungary, Iceland, Idaho, Illinois, Inner Mongolia, Iowa, Iran, Iraq, Ireland, Irkutsk, Italy, Japan, Kamchatka, Kansas, Kazakhstan, Kenya, Khabarovsk, Kirgizstan, Krasnoyarsk, Kriti, Krym, Kuril Is., KwaZulu-Natal, Labrador, Lebanon-Syria, Lesotho, Madagascar, Madeira, Magadan, Maine, Manchuria, Manitoba, Massachusetts, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Michigan, Minnesota, Mongolia, Montana, Morocco, Nebraska, Nepal, Netherlands, Nevada, New Brunswick, New Hampshire, New Mexico, New York, Newfoundland, North Carolina, North Caucasus, North Dakota, North European Russia, Northern Provinces, Northwest European Russia, Northwest Territories, Norway, Nova Scotia, Nunavut, NW. Balkan Pen., Ohio, Ontario, Oregon, Pakistan, Pennsylvania, Poland, Portugal, Primorye, Qinghai, Québec, Romania, Réunion, Sakhalin, Sardegna, Saskatchewan, Saudi Arabia, Sicilia, South Dakota, Spain, Sudan-South Sudan, Svalbard, Sweden, Switzerland, Tadzhikistan, Taiwan, Tanzania, Tasmania, Texas, Tibet, Transcaucasus, Tunisia, Turkmenistan, Tuva, Türkiye, Türkiye-in-Europe, Uganda, Ukraine, Utah, Uzbekistan, Vermont, Victoria, Virginia, Washington, West Himalaya, West Siberia, Wisconsin, Wyoming, Xinjiang, Yakutiya, Yemen, Yukon (POWO).

• Introduced into: Chatham Is. (POWO).

• ⚠️ Taxonomic note: A cosmopolitan and morphologically variable fern with numerous local forms. Cystopteris fragilis is readily recognised by its thin, brittle fronds, bipinnate structure, and reflexed indusia. It hybridises with related taxa (C. diaphana, C. alpina) in parts of its range. In Lebanon, it represents one of the few montane ferns thriving in high-altitude limestone habitats, typically near cold water sources.