Conifer cone

A cone (in formal botanical usage: strobilus, plural strobili) is an organ on plants in the division Pinophyta (conifers) that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity. The name 'cone' derives from the fact that the shape in some species resembles a geometric cone. The individual plates of a cone are known as scales.Spherical cone of Nootka cypress (Chamaecyparis nootkatensis)Long slender cones and winged seeds of California incense-cedar (Calocedrus decurrens) from the Muséum de ToulouseCones and wingless seeds of Chinese arborvitae (Platycladus orientalis) from the Muséum de ToulouseBerry-like cones of common juniper (Juniperus communis)A pine cone covered in ice after an ice storm.Male cones of a pineA classic example of a Lebanese Cedar cone.Immature female pine conePollen cone of a Japanese LarchPineapple gall on Sitka Spruce caused by Adelges abietis.Dozens of male cones (orange and flower-like) occur in a cluster; the female cone is still immature (olive green). Lodgepole Pine.Blue spruce with conesYoung female cones of loblolly pine receptive for pollination.Loblolly pine male cones ready to cast pollen.Cross section of maturing shortleaf pine cone showing seeds (arrows).Loblolly pine branch with cones of different ages; 2-yr old cones will disperse seeds during fall and winter.Cluster of Norway Spruce cones on Hokkaidō.Arborvitae cone.Pine cones jam (Ukraine).Pinus canariensis male cone in Gran Canaria.Photographs of the cone, front and back3D visualisation of the coneVarious sections through the 3D objectSemi-transparent viewMidsectionFlight around the 3D objectFlight through the µCT image stack, lateral viewFlight through the µCT image stack, top view A cone (in formal botanical usage: strobilus, plural strobili) is an organ on plants in the division Pinophyta (conifers) that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity. The name 'cone' derives from the fact that the shape in some species resembles a geometric cone. The individual plates of a cone are known as scales. The male cone (microstrobilus or pollen cone) is structurally similar across all conifers, differing only in small ways (mostly in scale arrangement) from species to species. Extending out from a central axis are microsporophylls (modified leaves). Under each microsporophyll is one or several microsporangia (pollen sacs). The female cone (megastrobilus, seed cone, or ovulate cone) contains ovules which, when fertilized by pollen, become seeds. The female cone structure varies more markedly between the different conifer families, and is often crucial for the identification of many species of conifers. The members of the pine family (pines, spruces, firs, cedars, larches, etc.) have cones that are imbricate (that is, with scales overlapping each other like fish scales). These pine cones, especially the woody female cones, are considered the 'archetypal' tree cones. The female cone has two types of scale: the bract scales, and the seed scales (or ovuliferous scales), one subtended by each bract scale, derived from a highly modified branchlet. On the upper-side base of each seed scale are two ovules that develop into seeds after fertilization by pollen grains. The bract scales develop first, and are conspicuous at the time of pollination; the seed scales develop later to enclose and protect the seeds, with the bract scales often not growing further. The scales open temporarily to receive gametophytes, then close during fertilization and maturation, and then re-open again at maturity to allow the seed to escape. Maturation takes 6–8 months from pollination in most Pinaceae genera, but 12 months in cedars and 18–24 months (rarely more) in most pines. The cones open either by the seed scales flexing back when they dry out, or (in firs, cedars and golden larch) by the cones disintegrating with the seed scales falling off. The cones are conic, cylindrical or ovoid (egg-shaped), and small to very large, from 2–60 cm long and 1–20 cm broad. After ripening, the opening of non-serotinous pine cones is associated with their moisture content—cones are open when dry and closed when wet. This assures that the small, wind disseminated seeds will be dispersed during relatively dry weather, and thus, the distance traveled from the parent tree will be enhanced. A pine cone will go through many cycles of opening and closing during its life span, even after seed dispersal is complete. This process occurs with older cones while attached to branches and even after the older cones have fallen to the forest floor. The condition of fallen pine cones is a crude indication of the forest floor's moisture content, which is an important indication of wildfire risk. Closed cones indicate damp conditions while open cones indicate the forest floor is dry.