Two ovules are formed at the end of a stalk, and after wind pollination, one or both develop into seeds. Male plants produce small pollen cones with sporophylls, each bearing two microsporangia spirally arranged around a central axis.įemale plants do not produce cones. Ginkgo biloba is dioecious, with separate sexes, some trees being female and others being male. These strategies are evidently important in the persistence of ginkgo in a survey of the "semiwild" stands remaining in Tianmushan, 40% of the specimens surveyed were multistemmed, and few saplings were present. Old individuals are also capable of producing aerial roots on the undersides of large branches in response to disturbances such as crown damage these roots can lead to successful clonal reproduction upon contacting the soil. It is capable of sprouting from embedded buds near the base of the trunk ( lignotubers, or basal chichi) in response to disturbances, such as soil erosion.
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Accordingly, ginkgo retains a prodigious capacity for vegetative growth. The species shows a preference for disturbed sites in the "semiwild" stands at Tianmu Mountains, many specimens are found along stream banks, rocky slopes, and cliff edges.
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Ginkgo prefers full sun and grows best in environments that are well-watered and well-drained. Ginkgo biloba cross section of tree trunk (source: Muséum de Toulouse) After a number of years, a short shoot may change into a long (ordinary) shoot, or vice versa. In ginkgos, as in other plants that possess them, short shoots allow the formation of new leaves in the older parts of the crown. Because of the short internodes, leaves appear to be clustered at the tips of short shoots, and reproductive structures are formed only on them (see pictures below – seeds and leaves are visible on short shoots). They are short and knobby, and are arranged regularly on the branches except on first-year growth. Short shoots have very short internodes (so they may grow only one or two centimeters in several years) and their leaves are usually unlobed. From the axils of these leaves, "spur shoots" (also known as short shoots) develop on second-year growth. Ginkgo branches grow in length by growth of shoots with regularly spaced leaves, as seen on most trees. During autumn, the leaves turn a bright yellow, then fall, sometimes within a short space of time (one to 15 days). Leaves are green both on the top and bottom and have stomata on both sides. They are borne both on the more rapidly growing branch tips, where they are alternate and spaced out, and also on the short, stubby spur shoots, where they are clustered at the tips. Leaves of long shoots are usually notched or lobed, but only from the outer surface, between the veins. Ginkgos are prized for their autumn foliage, which is a deep saffron yellow. The old common name, maidenhair tree, derives from the leaves resembling pinnae of the maidenhair fern, Adiantum capillus-veneris. The leaves are usually 5–10 cm (2–4 in), but sometimes up to 15 cm (6 in) long.
Two veins enter the leaf blade at the base and fork repeatedly in two this is known as dichotomous venation. The leaves are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never anastomosing to form a network. This misspelling was included by Carl Linnaeus in his book Mantissa plantarum II and has become the name of the tree's genus. It is considered that he may have misspelled "Ginkjo" as "Ginkgo". Įngelbert Kaempfer first introduced the spelling ginkgo in his book Amoenitatum Exoticarum. The spelling pronunciation / ˈ ɡ ɪ ŋ k ɡ oʊ/ is also documented in some dictionaries. ĭespite its spelling, which is due to a complicated etymology including a transcription error, "ginkgo" is usually pronounced / ˈ ɡ ɪ ŋ k oʊ/, which has given rise to the common alternative spelling "gingko".
The genus name is regarded as a misspelling of the Japanese pronunciation gin kyo for the kanji 銀杏 meaning "silver apricot", which is found in Chinese herbology literature such as 日用本草 (Daily Use Materia Medica) (1329) in volume 6, page 8 and Compendium of Materia Medica 本草綱目 published in 1578.
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