Althenia cylindrocarpa
(Korn. ex Müll.Stuttg.) Asch. Long-fruit Water-matPlants dioecious. Leaves not tapering distally; auricles 1–2 mm long; leaf margin entire; apex acute to acuminate or very shortly mucronate. Female flowers with pedicel 5–10 mm long; stigmas narrow, obliquely funnel-shaped, c. 0.2 mm wide, margin very slightly irregular. Male flowers with scales fused, small and cup-shaped; anther mass 6-locular; at anthesis the pedicels elongate to c. 10 mm long and extend the flowers beyond the leaf-sheath. Fruit smooth to slightly ridged or tuberculate dorsally, (1.5-)2–3 mm long (excluding style); fruiting pedicel 4–15 mm long, so fruit extended beyond the leaf-sheath. Flowers (Jul.–)Sep.–Mar.
Wim, VVP, MuF, GipP, OtP, WaP, GGr, DunT. Also SA, Tas. (Clarkes Is.). Occurs in marine estuaries, swamps and lakes, also in brackish water and sometimes in fresh water, or occasionally in streams.
Often confused with the closely related species Altehnia preissii. The most constant difference is that this species has larger fruits which extend beyond the scales and the pedicel extends the fruits beyond the leaf-sheath. In A. preissii the fruits are shorter than the subtending scales and the pedicel does not extend, so the fruits are usually not extended beyond the leaf-sheath.
Conn, B.J. (1994). Zannichelliaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons, pp. 156–160. Inkata Press, Melbourne.