tuber (L.) = swelling, hump. Referring to the coarsely tubercled culms.
WCM Protologue Reference:
Pillans, Ann. Bolus Herb. 3: 146 (1922)
Vegetative parts: plants several much-Branched culms from base, 0.6–1.2 m tall, compact, without spreading rhizomes or stolons. Fertile culms branching, roughly warty, olivaceous, 0.6–1.2 m tall, diameter at base 1–3.5 mm, diameter at apex 0.3–1.5 mm. Sheaths loosely convoluted, 5–30 mm long, pale brown to olivaceous, strongly tuberculate, apical margins narrowly membranous, hyaline shoulders tall, acute, hyaline shoulder 0.8–1.5 of sheath body length, apex, excluding the membranous lobes, acute or obtuse. Sheath-mucro penicellate, straight and erect, 2–10 mm long (equally the huge acute membranous shoulder lobes), very distinctive with the huge membranous shoulder lobes becoming lacerated. Males: male inflorescence with 2–5 spikelets or 6–10 spikelets or 11–20 spikelets or 21–50 spikelets or 50–100 spikelets, racemose or paniculate, 30–200 mm long, 5–30 mm wide. Male inflorescence spathes persistent, shorter than spikelets, coriaceous. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, oblong or elliptical, apex rounded, 4–12 mm, 3–6 mm, with 4–10 flowers, pedicels absent ie spikelets sessile or shorter than the spikelets, terete or angular. Male bracts shorter than flowers or as tall as flowers, 2–4 mm long, ovate, acuminate, margins shallowly toothed, cartilaginous, bract upper margin like body of bract, bract awn minute or absent, largely concolorous. Male flower 2–3 mm long. Male tepals sepals more rigid than petals, cartilaginous, petals membranous, oblong, inner and outer tepals the same length. Male outer lateral tepals conduplicate, keel sparsely villous. Anthers 1.2–1.6 mm long, exserted from the flowers. Pistillode present. Females: female inflorescence paniculate or racemose, 5–100 mm long, 5–50 mm wide, with 2–5 spikelets or 6–10 spikelets or 11–20 spikelets. Female spathes insignificant or shorter than the spikelets, persistent, coriaceous. Female spikelet sessile or pedicel simple, oblong or elliptical, apex rounded, 4–12 mm long, with 5–10 flowers, with 2–5 sterile bracts. Female bracts shorter than flowers, 1.5–3.5 mm long, ovate, acute or acuminate or apiculate, cartilaginous, apical margin like rest of bract, same as body of bract, awn minute or absent. Female flower 2.3–3.6 mm long, without a fleshy pedicel. Female tepals cartilaginous, keels of lateral sepals sparsely villous, midrib flush with the tepal body, apices rounded or acute, inner and outer whorls the same length. Female outer lateral tepals conduplicate, 2–3.8 mm long. Female odd outer tepal oblong or ovate, 2.2–3.2 mm long. Female inner tepals oblong or ovate, 2–3 mm long. Staminodes present. Styles feathery, 3. Style bases free. Ovary with 2 locules, dehiscent. Fruit: seed 1.2–1.6 mm long, 0.9 mm in diameter, shape in side view elliptical or oblong, shape in diameter triangular in cross section, tan, smooth (shiny).