Eleocharis sphacelata aka Tall Spikerush

Eleocharis sphacelata is a perennial water plant in the sedge family, Cyperaceae. Its native range covers New Guinea, Australia, and New Zealand. It is not native to Britain or Ireland. It grows in warm temperate and subtropical regions. In the tropics, it also occurs at high elevations. These records show a range that includes both lowland and mountain wetlands. They do not establish a frost tolerance for garden plants.

Its grass-like stems, called culms, rise from a woody rhizome. This thick underground stem creeps over short distances. It can reach about 0.4 inches (1 cm) thick. The Tropical Plants Database lists a height of 6.6 feet (2 m). However, stems in deep water can exceed 16.4 feet (5 m). The shorter figure offers a general size guide, not a proven cultivated range. The longer stems reflect growth in deep water rather than a fixed garden height. The supplied account gives no mature spread.

In eastern Australia, this sedge grows in fresh water with little movement. Records place it in water at least 16.4 feet (5 m) deep. In New Guinea, it grows in swamps high in the mountains. Those sites lie about 7,220–9,510 feet (2,200–2,900 m) above sea level. Its habitat supports treating it as an aquatic plant in cultivation. The evidence does not give light needs, soil preferences, or planting depths. Nor does it provide a hardiness zone or a detailed care guide.

People use the culms as material for woven rush skirts. This is the clear practical use recorded for the species. The database also lists seed as a means of propagation. It gives no sowing method or timing. The supplied sources do not describe the flowers or fruit in words. They also give no flowering season, pest records, or disease concerns. No specific landscape use is documented beyond its wetland habit.

Reports of food use conflict and need caution. One account describes round tubers that people eat without cooking. Another botanical account states that this species forms no tubers. The evidence therefore does not establish a dependable edible part. The database lists no known hazards, but that does not prove food safety. It also records no known medicinal use.