Conifer cone
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A conifer cone or pinecone (
The male cone (microstrobili 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
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.
Female cone of the conifer families
Pinaceae cones
The members of the
After ripening, the opening of non-
As a result of this, pine cones have often been used by people in temperate climates to predict dry and wet weather, usually hanging a harvested pine cone from some string outside to measure the humidity of the air.
Araucariaceae cones
Members of the Araucariaceae (Araucaria, Agathis, Wollemia) have the bract and seed scales fully fused, and have only one ovule on each scale. The cones are spherical or nearly so, and large to very large, 5–30 cm diameter, and mature in 18 months; at maturity, they disintegrate to release the seeds. In Agathis, the seeds are winged and separate readily from the seed scale, but in the other two genera, the seed is wingless and fused to the scale.
Podocarpaceae cones
The cones of the Podocarpaceae are similar in function, though not in development, to those of the Taxaceae (q.v. below), being berry-like with the scales highly modified, evolved to attract birds into dispersing the seeds. In most of the genera, two to ten or more scales are fused together into a usually swollen, brightly coloured, soft, edible fleshy aril. Usually, only one or two scales at the apex of the cone are fertile, each bearing a single wingless seed, but in Saxegothaea several scales may be fertile. The fleshy scale complex is 0.5–3 cm long, and the seeds 4–10 mm long. In some genera (e.g. Prumnopitys), the scales are minute and not fleshy, but the seed coat develops a fleshy layer instead, the cone having the appearance of one to three small plums on a central stem. The seeds have a hard coat evolved to resist digestion in the bird's stomach.
Cupressaceae cones
Members of the
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Spherical cone of Nootka cypress (Chamaecyparis nootkatensis)
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Long slender cones and winged seeds of California incense-cedar (Calocedrus decurrens)
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Cones and wingless seeds ofChinese arborvitae(Platycladus orientalis)
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Berry-like cones ofcommon juniper(Juniperus communis)
Sciadopityaceae cones
The cones and seeds of Sciadopitys (the only member of the family) are similar to those of some Cupressaceae, but larger, 6–11 cm long; the scales are imbricate and spirally arranged, and have 5-9 ovules on each scale.
Taxaceae and Cephalotaxaceae cones
Members of the yew family and the closely related Cephalotaxaceae have the most highly modified cones of any conifer. There is only one scale in the female cone, with a single poisonous ovule. The scale develops into a soft, brightly coloured sweet, juicy, berry-like aril which partly encloses the deadly seed. The seed alone is poisonous. The whole 'berry' with the seed is eaten by birds, which digest the sugar-rich scale and pass the hard seed undamaged in their droppings, so dispersing the seed far from the parent plant.
Welwitschiaceae cones
Location and distribution
For most species found in Australia, male and female cones occur on the same plant (
A further characteristic arrangement of pines is that the male cones are located at the base of the branch, while the female at the tip (of the same or a different branchlet). However, in larches and cedars, both types of cones are always at the tips of short shoots, while both sexes of fir cones are always from side buds, never terminal. There is also some diversity in bearing in Cupressaceae. Some, Cupressus for instance, have little or no differentiation in the positions of male and female cones.
Cone crops
Cone crop potential can be predicted in various ways. An early indication of a potential crop can be a period of abnormally hot, dry weather at the time of bud differentiation, particularly if the current and preceding cone crops have been poor (Nienstaedt and Zasada 1990).[3] Estimates of cone crop potential can be made by counting female reproductive buds in fall or winter, and an experienced observer can detect the subtle morphological differences and distinguish between reproductive buds and vegetative buds (Eis 1967b).[4]
White spruce seed collection is expensive, and collection from cone caches of red squirrels is probably the cheapest method. The viability of seed from cached cones does not vary during current caching, but viability drops essentially to zero after being in caches for 1 or 2 years (Wagg 1964).[5]
Collection of cones in seed orchards has been facilitated by the counter-intuitive technique of "topping" and collection of cones from the severed crown tops at one-third the cost of collection from untopped trees and without decreasing cone production (Slayton 1969, Nienstaedt 1981).[6][7]
Pseudocones
While alder trees are not conifers, their mature seed bearing structures closely resemble cones.
Cultural uses
Because of their widespread occurrence, conifer cones have been a traditional part of the arts and crafts of cultures where conifers are common. Examples of their use includes seasonal wreaths and decorations, fire starters, bird feeders, toys, etc.[8] An intriguing derivation of the impossible bottle mechanical puzzle takes advantage of the fact that pine cones open and close based on their level of dryness. In constructing the pine cone in the bottle display, a closed, damp cone of suitable size is inserted into a narrow-mouthed bottle and allowed to open upon drying.[9]
Cone cows are traditional homemade toys, made by children using material found in nature. The most common design is a spruce or pine cone with sticks or matches for legs, which can easily be attached by forcing them between the cone scales. Playing with cone cows often includes building an animal enclosure from sticks. For the most part, cone cows have been displaced by manufactured toys, at least in affluent countries, but the creation of cone cows still enjoys some popularity as an outdoor activity for children.
Cone cows are a part of children's culture in Finland where they are known as Käpylehmä (plural: Käpylehmät) and Sweden where they are known as kottkor or kottdjur (cone animals). Schools and other institutions teach children how to make cone cows as part of outdoors education on nature and history.
In Finland there is a fairground with cone cow sculptures large enough for children to ride on. In Sweden, a video game was released in which the player may build virtual cone cows.[10] Swedish artist Lasse Åberg has created artwork with cone cows, which has been included in an alphabet book[11] and featured on a Swedish postage stamp among other classic toys.[12][13]
Cones are also used as decorative elements in architecture such as on top of the posts surrounding Koper's Da Ponte Fountain, the central element of the Fontana della Pigna in Rome or a bronze cone in the narthex of the Aachen Cathedral. Cones are also occasionally used as a charge in heraldic coats of arms.
In some parts of Russia and Georgia, immature pine cones are harvested in late spring and boiled to make sweet preserves.[14]
Symbolism
The pineal gland is named after the pine cone.[15] Pine cones were also used as symbols of fertility in ancient Assyrian art. In Christian symbolism, they are closely related to the tree of life.[16]
See also
- Conifer nuts
- Parastichy
- Strobilus
Gallery
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A pine cone covered in ice after an ice storm.
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Male cones of a pine
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Female cone of a Lebanese cedar
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Immature female pine cone
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Pollen cone of aJapanese larch
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Sitka sprucecaused by Adelges abietis.
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Dozens of male cones (orange and flower-like) occur in a cluster; the female cone is still immature (olive green).Lodgepole pine.
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Blue spruce with cones
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Young female cones ofloblolly pinereceptive for pollination.
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Loblolly pinemale cones ready to cast pollen.
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Cross section of maturingshortleaf pinecone showing seeds (arrows).
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Loblolly pinebranch with cones of different ages; two-year old cones will disperse seeds during fall and winter.
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Cluster ofHokkaidō.
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Arborvitae cone.
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Pine cones jam (Ukraine).
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Pinus canariensis male cone in Gran Canaria.
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Pine cones
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More pine cones
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The cone structure of Abies bracteata
Visualisation of a Cupressus cone by micro computed tomography
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Photographs of the cone, front and back
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3D visualisation of the cone
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Various sections through the 3D object
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Semi-transparent view
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Midsection
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Flight around the 3D object
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Flight through the µCT image stack, lateral view
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Flight through the µCT image stack, top view
References
- ^ Dawson, Colin; Vincent, Julian F. V.; Rocca, Anne-Marie. 1997. How pine cones open. Nature 390: 668.
- ^ "Ask a Scientist: Pine Cone Wet and Dry". Newton.dep.anl.gov. Archived from the original on 2015-02-26. Retrieved 2013-08-30.
- ^ Nienstaedt, Hans; Zasada, John C. (1990). "Picea glauca". In Burns, Russell M.; Honkala, Barbara H. (eds.). Conifers. Silvics of North America. Vol. 1. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA) – via Southern Research Station.
- ^ Eis, S. 1967b. Cone crops of white and black spruce are predictable. For. Chron. 43(3):247–252.
- ^ Wagg, J.W.B. 1964. Viability of white spruce seed from squirrel-cut cones. For. Chron. 40(1):98–110.
- ^ Slayton, S.H. 1969. A new technique for cone collection. USDA, For. Serv., Tree Plant. Notes 20(3):13. (Cited in Nienstaedt and Zasada 1990).
- ^ Nienstaedt, H. 1981. Top pruning white spruce seed orchard grafts does not reduce cone production. USDA, For. Serv., Tree Plant. Notes 32(2):9–13. (Cited in Coates et al. 1994).
- ^ "Pine Cone Craft Projects". Familycrafts.about.com. 2013-08-23. Archived from the original on 2013-05-11. Retrieved 2013-08-30.
- ^ zupperzipper (2008-07-13). "Pine Cone in the Bottle Display". Instructables. Retrieved 2013-08-30.
- ^ Kapsyljakt med Anki och Pytte review "You build cone cows"
- ^ Åbergs ABC[permanent dead link] "a little book about cone cows, small fears, swarming helicopters and such"
- ^ Posten.se press release Archived 2010-09-13 at the Wayback Machine "Motives include [..] life in the countryside, which shows both the cone cow, a doll in a traditional outfit, and a horse and carriage toy"
- ^ Livet på landet image of the stamp from the official postal site
- ^ "Pine Cone Preserves". Atlas Obscura.
- ^ "Pineal (as an adjective)". Online Etymology Dictionary, Douglas Harper. 2018. Retrieved 27 October 2018.
- ^ The Continuum Encyclopedia of Symbols by Udo Becker (2000) Page 234
External links
- Arboretum de Villardebelle Images of various conifer-cones
- Gymnosperm cone images at bioimages.vanderbilt.edu