congestus (L.) = collecting, heaping together. The name might refer to the overlapping female spikelets.
WCM Protologue Reference:
Mast., Fl. Cap. 7: 143 (1897)
Vegetative parts: plants tufted (Often with culms bending down), 0.5-1 m tall, basal diameter 0.2-0.5 m, crown diameter 0.3-1 m, compact, without spreading rhizomes or stolons. Fertile culms unbranched, distinctly hollow, smooth or finely rugulose, green or speckled golden, 0.5-1 m tall, diameter at base 1-2 mm, diameter at apex 1-2 mm. Sheaths closely convoluted, 20-60 mm long, brown, often with golden speckling and longitudinal striations, the lower 1/3 of the sheath often green, apical margins broadly membranous or broadly chartaceous and soon decaying, hyaline shoulders absent, apex, excluding the membranous lobes, acute (or variable). Sheath-mucro penicellate, straight and erect, 2-6 mm long. Males: male inflorescence with 11-20 spikelets or 21-50 spikelets or 50-100 spikelets, paniculate, 30-90 mm long, 7-30 mm wide. Male inflorescence spathes caducous, taller than spikelets, cartilaginous, Drop off before anthesis, thus not obscuring the spikelets. Male flowers in spikelets. Male spikelets erect on stiff pedicels or sessile, ovate or orbicular, apex rounded or obtuse or acute, 3-4.5 mm, 2.5-5 mm, with 10-20 flowers, pedicels shorter than the spikelets, terete or angular. Male bracts as tall as flowers or taller than flowers, 2-3.5 mm long, ovate, acuminate, cartilaginous, bract upper margin membranous, thinner texture than the body, bract awn minute or absent or less than half as long as the bract body, pale brown, acuminate, awn about half as long as the bract. Male flower 1.7-2.5 mm long. Male tepals sepals and petals the same rigidity, chartaceous or membranous, oblong, inner and outer tepals the same length (truncate to rounded). Male outer lateral tepals keeled or winged or conduplicate, glabrous. Anthers 1-1.5 mm long, exserted from the flowers. Pistillode absent. Females: female inflorescence linear, 25-60 mm long, 5-18 mm wide, with 1 spikelet or 2-5 spikelets. Female spathes as long as the spikelets or longer than the spikelets, not obscuring spikelet, persistent, cartilaginous. Female spathellae inconspicuous or absent. Female spikelet sessile, oblong or elliptical, apex acute, 15-28 mm long, with 2 flowers, with 3-5 sterile bracts. Female bracts taller than flowers, 10-40 mm long, ovate, acuminate, bony or coriaceous, apical margin like rest of bract or membranous, same as body of bract, awn minute or absent or less than half as long as the bract body. Female flower with a fleshy pedicel. Female tepals membranous, glabrous and smooth, at least as tall as nut, wrapped around it and obscuring the surface or smaller than nut and not obscuring the nut surface, midrib flush with the tepal body, apices rounded or obtuse or acute, inner and outer whorls the same length. Female outer lateral tepals like other tepals, 1.5-7 mm long (mostly 5-7, single collection from Tulbagh Waterfall that is less than 5). Female odd outer tepal oblong, 1.5-7 mm long (mostly 5-7, single collection from Tulbagh Waterfall that is less than 5). Female inner tepals linear or oblong, 1.5-7 mm long (mostly 5-7, single collection from Tulbagh Waterfall that is less than 5). Staminodes absent. Styles plumose, white, 2. Style bases free. Ovary with 1 locule, indehiscent. Fruit: indehiscent fruits with a hard woody ovary wall. Perianth presence on fruits persistent, membranous, as tall as nuts or persistent, membranous, shorter than nut (mostly as long as the nut, single collection from Tulbagh Waterfall that is less shorter than the nut). Nut apex smooth, without a distinct cap, wall smooth, (5.33-)6.57(-7.67) mm long, (2.67-)2.91(-3.33) mm diam., shape in side view oblong, shape in top view planoconvex in cross section, black. Elaiosome present, white, 1.2-1.6 mm long, less than half as long as nut.