Word Finder - strobilus

definition

A cone-shaped fruiting body in general

definition

More particularly a more-or-less cone-shaped fruiting body of any of various gymnosperms and vascular sporophytes. According to source and context it might refer to a structure bearing either seeds or spores, that might or might not be seen as an infructescence; usage has varied arbitrarily among authors during the last two centuries.

definition

A layered reproductive stage in jellyfish, in which the swimming medusa form is produced.

C, Fertile shoot showing two leaf-sheaths and the terminal strobilus.

Abnormal specimens of Equisetum in which the strobilus is interrupted by whorls of leaves are of interest for comparison with the fructification of Phyllotheca.

This similarity is closest in Archaeocalamites, an ancient type found in Upper Devonian rocks; in this the strobilus consists of peltate sporangiophores inserted in whorls on the axis.

Though the high specialization of this ancient group of plants renders the determination of their natural affinities difficult, indications are afforded by anatomy and the morphology of the strobilus.

The plant is reproduced by tubers, which resemble the protocorm in bearing first a number of protophylls and later the upright shoot with its single terminal strobilus.

A lengthening of the axis of the female strobilus of Coniferae is not of infrequent occurrence in Cryptomeria japonica, larch (Larix europaea), &c., and this is usually associated with a leaf-like condition of the bracts, and sometimes even with the development of leaf-bearing shoots in place of the scales.

This form of strobilus, from the Coal Measures of Germany, is imperfectly known, and its relation to Calamarieae not beyond doubt.

In the peduncle of the strobilus secondary tissues are formed.

The seed-like body was detached as a whole from the cone, and in this condition was known for many years under the name of Cardiocarpon anomalum, having been wrongly identified with a true Gymnospermous seed so named a seed are obvious; the which is not tubular, but forms a long crevice, running in a direction radial to the strobilus.

The female fructification is in the form of a rather lax strobilus.

In Selaginellites Suissei there was a definite strobilus bearing both microand megasporangia; in each of the latter from 16 to 24 megaspores were contained; in Selaginellites primaevus, however, the number of megaspores was only 4, and the resemblance to a recent Selaginella was thus complete.

Selaginellites elongatus, another heterosporous species, is remarkable for having no differentiated strobilus, a condition not known in the recent genus.