Isoetes drummondii subsp. anomala C.R.Marsden & Chinnock APNI*
Description: Annual plant; corm small, usually 2 or (3)-lobed, to 10 mm wide.
Leaves to 30, spirally arranged, erect or recurved, 3–13 (-30) cm long, 1–2 mm diam., acute, bright green; base to 20 mm wide, broadly winged, very dilated, bases of the outer leaves completely covering the bases of the inner ones, white; peripheral fibre strands 2–4, rarely with small accessory ones; stomata present distally; internal hairs absent; trans-lacunar diaphragms visible; ligule triangular-cordate, 1–2 mm long; labium small.
Sporangia naked, not covered by a velum, round to obovate or elongate-elliptic, c. 5 mm diam.; wall opaque, shiny, dark brown; megaspores irregular, large, often 0.5 mm diam., Type III with only a few Type I; proximal and distal faces tuberculate; tubercles often coalescing into short irregular cristae, drying white; microspores not known.
Distribution and occurrence: Found in south-eastern S.A. and Vic., with isolated populations in southern N.S.W. (rare south from Goulburn) and south-western W.A.
In shallow water or mud.
NSW subdivisions: ST, SWS
Other Australian states: Vic.
"Type I megaspores: almost spherical, nucleate and containing large quantities of fats, oils and other storage products; usually fertile. Type III megaspores: irregular, dumbbell-shaped, usually appearing like parts of two type I megaspores joined together by one or more tubular connections; probably binucleate and containing storage products; possibly fertile."
Text by E.A. Brown
Taxon concept: Flora of Australia 48
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.