 The leaves are opposite, 3–7 cm long and 1.5–4 cm broad with a thick, leathery texture, lustrous dark green above, paler yellow-green below; the margin is entire or with one to four large spine-tipped teeth on each side.Spiny leaves predominate on small, young plants (an adaptation to deter browsing animals), while entire leaves predominate higher on larger mature plants out of the reach of animals.The flowers are very fragrant, white, with a four-lobed corolla, the corolla tube 1–2 mm long and the lobes 2.5–5 mm long; they are dioecious, with flowering in the autumn.