Rhizomes creeping, with internodes up to 4.8 cm, but internodes occasionally shorter and fronds then appearing tufted; roots arising both at nodes and 1 or 2 on internodes, short shoots 1-3 mm occasionally formed at nodes; main rhizome sparsely pubescent to glabrate. Fronds with stipes green to straw-colored, 10-18 cm, slender, glabrate; pinnae obtriangular to fan-shaped, 0.8-1.6 × 0.7-1.5 cm, margin entire, glabrate above, sparely appressed-pubescent to glabrate below. Sporocarps (1 or)2-5(-7) per frond, attached at base of stipe where stipe joins rhizome or up to 25 mm up stipe, sometimes persistent after decay of frond and then appearing to arise directly from rhizome; peduncles 5-12.5 mm (when 2 or 3 sporocarps on a frond these attached to stipe by a common peduncle 2-8 mm), plus an additional 1.5 mm adnate to sporocarp, glabrate; sporocarp brown to black, elliptic in lateral view, 3.5-4 × 2.9-3.2 × ca. 2 mm, softly leathery, convex on lateral sides, obtuse to rounded on perimeter, usually marked with a distinct tooth 0.3-0.4 mm above end of peduncle, densely appressed-pubescent when young, becoming thinly pubescent to glabrate with age.
Plants forming diffuse clones. Roots arising at nodes and 1--3 on internodes. Petioles 5.4--16.5 cm, sparsely pubescent to glabrous. Pinnae 7--21 × 6--19 mm, sparsely pubescent to glabrous. Sporocarp stalks ascending, frequently branched, attached 1--12 mm above base of petiole; unbranched stalks or ultimate branches of stalks 3--16 mm; common trunk of branched stalks 1--4 mm (rarely 2--3 unbranched stalks attached separately to same petiole). Sporocarps perpendicular to ascending, 4--5.6 × 3--4 mm, 2.3--2.8 mm thick, rounded, oval, or elliptic in lateral view, pubescent but soon glabrate; raphe 1.4--1.9 mm, proximal tooth usually absent, distal tooth absent or 0.1--0.2 mm. Sori 10--17.
"Rhizome rooting between as well as the nodes; petioles to 30 cm; lfls glabrous or nearly so, those of emergent lvs 7–30 mm long and wide, those of floating lvs avg a little larger; peduncle attached 1–12 mm above the base of the petiole, 3–20 mm, simple or often branched 1–4 mm above its base to bear 2 or 3 sporocarps; sporocarp 4–5.5 × 3–4 mm, 2.5 mm thick, hairy when young, soon glabrate, the inferior tooth mostly wanting, the superior one wanting or to 0.2 mm; sori 10–17 per sporocarp, with ca 12 microsporangia and 3–7 megasporangia per sorus. In quiet shallow water; native of Europe, locally escaped and established in our range."
Blätter 8–15 cm hoch, mit lang gestielter, 4teiliger, kleeblattartiger, oft auf der Wasseroberfläche schwimmender Spreite, Teilblätter breit gerundet, keilförmig verschmälert, ganzrandig. Sporangienhüllen (Sporokarpien) am Grund der Blattstiele auf
Rizom ince, sürünücü. Yaprak 1,6-2,57 cm çapında; yaprak sapı 4,3-7,9 cm uzunluğunda, çıplak; aya dört yaprakçıklı; yaprakçıklar 4-8,5 x 6,7-14,5 mm, tabanda kamamsı. Olgun sporokarp bilinmiyor (Türkiye’de).
|Trifoglio acquatico comune||Italian||CH|
|Marsilée à quatre feuilles||French||CH|