insignis (L.) = remarkable for, outstanding, noted.
WCM Protologue Reference:
Mast., Gard. Chron., III, 25: 242 (1899)
Vegetative parts: plants tufted, 1–2 m tall, basal diameter 0.1–0.4 m, crown diameter 0.4–1 m, compact, without spreading rhizomes or stolons. Fertile culms unbranched, smooth, olivaceous, 1–2 m tall, diameter at base 1.3–3.5 mm, diameter at apex 1–2 mm. Sheaths closely convoluted, 20–50 mm long, brown to grey, apical margins broadly chartaceous and soon decaying, hyaline shoulders absent, apex, excluding the membranous lobes, acute. Sheath-mucro absent or penicellate, straight and erect, 0–3 mm long.
Males: male inflorescence with 21–50 spikelets or 50–100 spikelets, paniculate, 50–250 mm long, 30–50 mm wide. Male inflorescence spathes persistent, upper margins lacerated and largely decayed at anthesis, shorter than spikelets, chartaceous. Male flowers in spikelets. Male spikelets pendulous on flexible pedicels, linear or oblong, apex rounded, 8–20 mm, 3–4 mm, with 12–40 flowers, pedicels shorter than the spikelets, flattened. Male bracts as tall as flowers or taller than flowers, 3–4.5 mm long, oblong or ovate, acute, chartaceous, bract upper margin like body of bract, bract awn minute or absent, brick-red. Male flower 2–3 mm long. Male tepals sepals and petals the same rigidity, chartaceous, linear, inner and outer tepals the same length. Male outer lateral tepals conduplicate, glabrous. Anthers 1.3–1.7 mm long, included in the flowers. Pistillode absent.
Females: female inflorescence linear or paniculate or racemose, 80–400 mm long, 10–30 mm wide, with 11–20 spikelets or 21–50 spikelets. Female spathes shorter than the spikelets or as long as the spikelets, persistent, chartaceous. Female spikelet pedicel simple or pedicel sparsely branching, oblong, apex rounded, 15–45 mm long, with 8–40 flowers, with 0 sterile bracts. Female bracts at least twice as long as flowers, 7–10 mm long, oblong or ovate, acute, chartaceous or cartilaginous, apical margin like rest of bract, same as body of bract, awn minute or absent. Female flower 3–4.5 mm long, without a fleshy pedicel. Female tepals cartilaginous, glabrous and smooth, at least as tall as nut, wrapped around it and obscuring the surface, midrib flush with the tepal body, apices obtuse or acute, inner whorl shorter than outer. Female outer lateral tepals keeled or winged, wings entire, wings lateral sepals decurrent, without grooves, wider than body, 3–4.5 mm long. Female odd outer tepal oblong, 2.4–3 mm long. Female inner tepals oblong, 2–2.7 mm long. Staminodes absent. Styles plumose, white, 1. Ovary with 1 locule, indehiscent.
Fruit: indehiscent fruits with a softer ovary wall. Perianth presence on fruits persistent, winged. Shape of winged dispersal unit orbicular. Nut apex smooth, without a distinct cap, wall smooth (rough in apical half, with tuberculate cells), (1.4–)1.61(–1.76) mm long, (1–)1.12(–1.24) mm diam., shape in side view ovate, shape in top view elliptical in cross section, brown. Elaiosome absent.