Pinus nigra is a large coniferous evergreen tree, growing to 20–55 metres (66–180 ft) high at maturity and spreading to 20 to 40 feet wide. The bark is grey to yellow-brown, and is widely split by flaking fissures into scaly plates, becoming increasingly fissured with age. The leaves ("needles") are thinner and more flexible in western populations (see 'Taxonomy' section below). The ovulate and pollen cones appear from May to June. The mature seed cones are 5–10 cm (rarely to 11 cm) long, with rounded scales; they ripen from green to pale grey-buff or yellow-buff in September to November, about 18 months after pollination. The seeds are dark grey, 6–8 mm long, with a yellow-buff wing 20–25 mm long; they are wind-dispersed when the cones open from December to April. maturity is reached at 15–40 years; large seed crops are produced at 2–5 year intervals. Pinus nigra is moderately fast growing, at about 30–70 centimetres (12–28 in) per year. It usually has a rounded conic form, that becomes irregular with age. The tree can be long-lived, with some trees over 500 years old. It needs full sun to grow well, is intolerant of shade, and is resistant to snow and ice damage.