European chestnut

C. sativa attains a height of 20–35 m (66–115 ft) with a trunk often 2 m (7 ft) in diameter. The bark often has a net-shaped (retiform) pattern with deep furrows or fissures running spirally in both directions up the trunk. The trunk is mostly straight with branching starting at low heights. Sweet chestnut trees live to an age of 500 to 600 years. In cultivation they may even grow as old as 1000 years or more. Their large genetic diversity and different cultivars are exploited for uses such as flour, boiling, roasting, drying, sweets or wood. The oblong-lanceolate, boldly toothed leaves are 16–28 cm (6–11 in) long and 5–9 cm (2–4 in) broad. ReproductionEdit The flowers of both sexes are borne in 10–20 cm (4–8 in) long, upright catkins, the male flowers in the upper part and female flowers in the lower part. In the northern hemisphere, they appear in late June to July, and by autumn, the female flowers develop into spiny cupules containing 3-7 brownish nuts that are shed during October. The female flowers eventually form a spiky sheath that deters predators from the seed. The sweet chestnut is self incompatible, meaning that the plant cannot pollinate itself, making cross-pollination necessary. Some cultivars only produce one large seed per cupule, while others produce up to three seeds. The nut itself is composed of two skins: an external, shiny brown part, and an internal skin adhering to the fruit. Inside, there is an edible, creamy-white part developed from the cotyledon.