According to the most recent genetic research, bur-reeds are most closely allied to cattails, and they grow in similar conditions. Botanists now place them in the cattail family Typhaceae, but until recently they were usually given their own family, Sparganiaciae. The burs are rather fierce-looking but decorative in an odd way. This clump was growing at the edge of a pond near Normalville, where it was showing off its burs in the middle of August.
Gray describes the genus and the species:
Spargànium [Tourn.] L. BUR-REED. Heads scattered along the upper part of the simple or sparingly branched leafy stem, the bracts caducous or the lower persisting and leaf-like. — Perennials with fibrous roots and creeping horizontal rootstocks. Flowering through the summer. The fertile heads becoming bur-like from the divergent beaks, bat the pistils at maturity falling away separately. (Name ancient, probably from sparganon, a band, in allusion to the ribbon-like leaves.)
Fertile flowers closely sessile: fruit brondly obovoid.
S. eurycárpum Kngelm. Stems stout, erect (8-13 dm. high); leaves mostly flat and merely keeled; pistil attenuate into a short style bearing 1 or 2 elongated stigmas; fruit heads 2-6 or more. 2-3 cm. in diameter; fruit angled, often 2-seeded, 7-8 mm. long when mature, with a broad and depressed or retuse summit abruptly tipped in the center. — Borders of ponds, lakes, and rivers, N. S. and Me., southw., and westw. to the Pacific, chiefly at low altitude.