The Collaborative International Dictionary
Columella \Col`u*mel"la\, n. [L., dim. of columen column. See Column.]
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(Bot.)
An axis to which a carpel of a compound pistil may be attached, as in the case of the geranium; or which is left when a pod opens.
A columnlike axis in the capsules of mosses.
(Anat.) A term applied to various columnlike parts; as, the columella, or epipterygoid bone, in the skull of many lizards; the columella of the ear, the bony or cartilaginous rod connecting the tympanic membrane with the internal ear.
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(Zo["o]l.)
The upright pillar in the axis of most univalve shells.
The central pillar or axis of the calicles of certain corals.
Wiktionary
n. 1 (context biology English) Any of various small structures in plants or animals that are columnar in shape. 2 (context anatomy English) The skin at the end of the septum which separates the nostrils. 3 (context comparative anatomy English) In birds, reptiles, and amphibians, the small bone which carries vibration from the tympanum to the inner ear. 4 (context malacology English) In gastropods, the structure at the center of the whorls of the shell. 5 (context coral science English) The structure at the center of the calyx where the septa join together. 6 (context mycology English) The central sterile portion of the sporangium in various fungi. 7 (context palynology English) A rod-shaped reinforcing element of the sexine layer of a pollen grain.
WordNet
n. a small column (or structure resembling a column) that is a part of a plant or animal
[also: columellae (pl)]
Wikipedia
Lucius Junius Moderatus Columella (; 4 – c. 70 AD) is the most important writer on agriculture of the Roman empire. Little is known of his life. He was probably born in Gades, Hispania Baetica (modern Cádiz), possibly of Roman parents. After a career in the army (he was tribune in Syria in 35), he took up farming. His Res rustica in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the works of Cato the Elder and Varro, both of which he occasionally cites. A smaller book on trees, De arboribus, is usually attributed to him.
Columella used many sources no longer extant, to which he is one of the few references; these include Aulus Cornelius Celsus, the Carthaginian writer Mago, Tremellius Scrofa, and many Greek sources. His uncle Marcus Columella, "a clever man and an exceptional farmer" (VII.2.30), had conducted experiments in sheep breeding, crossing colourful wild rams, introduced from Africa for gladiatorial games, with domestic sheep, and may have influenced his nephew's interests. Columella owned farms in Italy; he refers specifically to estates at Ardea, Carseoli, and Alba, and speaks repeatedly of his own practical experience in agriculture.
Previously known only in fragments, the complete treatise of Columella was among those discovered in monastery libraries in Switzerland and France by Poggio Bracciolini and his assistant Bartolomeo di Montepulciano during the Council of Constance, between 1414 and 1418.
In 1794 the Spanish botanists Jose Antonio Pavón y Jimenez and Hipólito Ruiz López named a genus of Peruvian asterid Columellia in his honour.
Columella is Latin meaning "little column". It may refer to:
- Columella (4 - ca. 70), a Roman writer
Columella is a genus of very small, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Vertiginidae, the whorl snails.
The columella (meaning "little column") or (in older texts) pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image.
The columella runs from the apex of the shell to the midpoint of the undersurface of the shell, or the tip of the siphonal canal in those shells which have a siphonal canal. If a snail shell is visualized as a cone of shelly material which is wrapped around a central axis, then the columella more or less coincides spatially with the central axis of the shell. In the case of shells that have an umbilicus, the columella is a hollow structure.
The columella of some groups of gastropod shells can have a number of plications or folds (the columellar fold, plaits or plicae), which are usually visible when looking to the inner lip into the aperture of the shell. These folds can be wide or narrow, prominent or subtle. These features of the columella are often useful in identifying the family, genus, or species of the gastropod.
The surface of the columella is called the columellar wall. The columellar callus is a smooth, calcareous thickening, secreted by the mantle, extending over the columellar area. The columellar lip, the visible part of the columella, is the lower part of the inner lip and is situated near the axis of coiling. A columellar tooth is a raised projection on the inner lip of a columella in the direction of the aperture.
Columella (in plants), an axis of sterile tissue which passes through the center of the spore-case of mosses.
In the auditory system, the columella is a bone that contributes to hearing in amphibians, reptiles and birds, corresponding to the stapes in mammals.
In humans, artificially made columellas, such as made as autografts from cortical bone, are used as replacements for the stapes in ear surgery to correct for, for example, hearing problems, cholesteatoma or re-perforation.
Usage examples of "columella".
In the Andreaeales the columella does not extend to the upper end of the capsule, and the latter opens by a number of lateral slits.
The Anthocerotales are a small and very distinct group, in which the gametophyte is a thallus, while the sporogonium possesses a sterile columella and is capable of long-continued growth and spore production.
The archesporium arises by the next divisions in the outer layer of cells, and thus extends over the summit of the columella.
In some species, although the columella and archesporium arise in the usual way, both give rise to mingled spores and elaters, and no sterile columella is developed.
The development of the sporogonium proceeds as in the Bryales, but the dome-shaped archesporium extends over the summit of the columella and an air-space is wanting.
The spores are derived from the endothecium, but no distinction of a sterile columella and an archesporium is established in this, a variable number of its cells becoming spore-mother-cells while the rest serve to nourish the spores.
In all other Bryales there is a definite columella extending from the base to the apex of the capsule, the archesporium is derived from the outermost layer of cells of the endothecium, and an air space is formed between the spore-sac and the wall.
In the Polytrichaceae another air space separates the spore-sac from the columella.
The Sphagnales also have a dome-shaped spore-sac continued over the columella, and, though their capsule opens by an operculum, they differ widely from other mosses in the development of the sporogonium as well as in the characters of the sexual generation.
Vicarius Columella raised his hands, smiling as if he were a merchant whose price has just been battered down by hard bargaining.
This impromptu and judicious amendment was greeted with cheers all around, and Imperial Vicarius Columella smiled as graciously as if he had intended offering the increase from the first.
General Septimus and Vicarius Columella, surrounded by a bodyguard of soldiers, were among the last to come.
Aulus Columella, by appointment of Emperor Honorius, Consul and Vicarius of Gaul and Germania, do herewith promote you, Succat, to the rank of centurion in the Imperial Army of Rome.
Vicarius Columella professed to find this tale fascinating, so I gave him a much-reduced version of the events which had led me to enroll as a mercenary in the Gaulish auxiliary.
I slept long and could have slept far longerbut for Rufus shaking me awake with the news that Vicarius Columella demanded to see me at once.