| General Information |
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| Distribution | A genus comprised about 10 species, which are confined to Madagascar and
the Mascarene Islands in the Indian Ocean, India, and continental eastern Asia, Australia, Malesia, Melanesia, and
Polynesia (to the Society and Austral Islands). A single species, M. torresiana, is widely introduced and
abundantly naturalized in the New World tropics and subtropics.
A genus of about ten species ranging from tropical to subtropical Asia, Australia, Malesia, Pacific islands, and Africa.
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Habit
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Terrestrial, fronds of determinate growth, mostly medium-sized to very large, 50–200+ cm tall. Rhizomes
short-creeping to ascending or suberect, to 1 cm diameter, with brown to tan scales, these lanceolate, with scattered hairs along margins and sometimes sparingly on surface.
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Leaves
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Fronds clustered, monomorphic, evergreen or dying in winter; stipe to 80 cm long, 12 mm diameter, not grooved adaxially, green or stramineous, less often castaneous, sometimes glaucous, scales lanceolate, stramineous to brown, 2–20 mm long, thickened at their bases, usually with a hairlike tip, typically with marginal and superficial hairs and often with stipitate glands; blade herbaceous to chartaceous, broadly deltate, to 1 m long, usually broadest at base or with proximal pinnae only slightly reduced (always lacking greatly reduced glanduliform pinnae), lacking buds or proliferations, pinnate-pinnatifid to bipinnate- or even tripinnate-pinnatifid, apex gradually tapering and pinnatifid; rachis adaxially not grooved, bearing simple acicular, often septate hairs, sometimes with persistent scales that leave a stump or “wart” when breaking off; pinnae to 15–35 cm, subopposite proximally to alternate distally, subsessile or stalked, distal pinnae increasingly adnate, spreading or obliquely spreading, not grooved adaxially, truncate at bases, acute at tips, to ca. 15(–20) long × 2(–3) cm wide, pinnatifid or pinnate-pinnatifid with pinnules adnate and sometimes interconnected at their bases, in larger species free, with or without acroscopic and/or basiscopic, more lobed basal auricles, sessile or nearly so; veins free, often forking in ultimate segments, ± easily visible on both sides, vein ends clavate adaxially and not reaching segment margins; aerophores absent at pinna bases; indument abaxially usually of sparse to moderately dense unicellular or often septate hyaline acicular hairs 0.5–2 mm long, in some species also with costal scales, blade often glabrescent with age, short-stipitate pale yellowish glands sometimes present along costae and costules; indument adaxially of hyaline acicular hairs to ca. 1 mm long along costae, sometimes also with hairs and stalked glands on costules and ultimate veins, occasionally on laminar tissue between veins; pustules absent on laminae between veins.
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Sori
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Sori medial to supramedial, round, exindusiate or usually with small indusia to ca. 0.3 mm diameter (often hidden in mature sori), sori not confluent at maturity; sporangia glabrous or with 1–3 short-stipitate glands ca. 0.05 mm long adjacent to annulus on capsule, sporangial stalks short.
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Spores
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Spores tan to brown, ± winged or with a fine reticulate network, but lacking a low polygonal network of ridges.
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Chromosomes
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x = 31
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Notes
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The generic name is derived from the Greek makros, large + Thelypteris. This genus has some of the largest and most deeply dissected (tripinnate-pinnatifid) fronds in the family.
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Contributor
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Nancy Khan
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