1878: George Bentham, Handbook of the British flora, p415 (Brook)Low, creeping, heath-like shrubs, with small, crowded, entire, evergreen, leaves, and minute, axillary, diœcious flowers.
1879: Asa Gray, Manual of the Botany of the Northern United States, p273 (Ivison, Blakeman, Taylor & co.)Heads many-flowered ; the flowers all tubular, perfect and similar, or rarely imperfectly diœcious. Scales of the ovoid or spherical involucre imbricated in many rows, tipped with a point or prickle.