Pl. aculei. [L., = a sting, dim. of acus a needle.]
1. Zool. The sting of an insect or other animal.
1828. Kirby & Spence, Entomol., IV. xlii. 162. The valves are linear, exserted, and as long as the aculeus itself.
2. Bot. ‘A prickle; a conical elevation of the skin of a plant, becoming hard and sharp-pointed: as in the rose.’ Lindley, in Treas. of Bot.
1878. M‘Nab, Bot., 76. Prickles or aculei occurring on some brambles and roses, differ from true hairs in their originating from the epidermis, and one or more cells below it.
