pollen tube
Spermatophyta Sper`ma*toph"y*ta, n. pl. [NL.; spermato- + Gr. ? plant.] (Bot.) A phylum embracing the highest plants, or those that produce seeds; the seed plants, or flowering plants. They form the most numerous group, including over 120,000 species. In general, the group is characterized by the marked development of the sporophyte, with great differentiation of its parts (root, stem, leaves, flowers, etc.); by the extreme reduction of the gametophyte; and by the development of seeds. All the Spermatophyta are heterosporous; fertilization of the egg cell is either through a

{pollen tube} emitted by the microspore or (in a few gymnosperms) by spermatozoids.

Note: The phrase ``flowering plants'' is less distinctive than ``seed plants,'' since the conifers, grasses, sedges, oaks, etc., do not produce flowers in the popular sense. For this reason the terms {Anthrophyta}, {Ph[ae]nogamia}, and {Panerogamia} have been superseded as names of the phylum by Spermatophyta. [Webster 1913 Suppl.]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Pollen tube — Pollen Pol len, n. [L. pollen fine flour, fine dust; cf. Gr. ?] 1. Fine bran or flour. [Obs.] Bailey. [1913 Webster] 2. (Bot.) The fecundating dustlike cells of the anthers of flowers. See {Flower}, and Illust. of {Filament}. [1913 Webster]… …   The Collaborative International Dictionary of English

  • pollen tube — n. Bot. the tubelike growth that emerges from a germinating pollen grain and enters the embryo sac in an ovule: a male gamete passes through it to fertilize the female gamete …   English World dictionary

  • pollen tube — pollen tube. См. пыльцевая трубка. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Pollen tube — The pollen tube of most seed plants acts as a conduit to transport sperm cells from the pollen grain, either from the stigma (in flowering plants or angiosperms) to the ovules at the base of the pistil, or directly through ovule tissue in some… …   Wikipedia

  • pollen tube — noun (botany) a slender tubular outgrowth from a pollen grain when deposited on the stigma for a flower; it penetrates the style and conveys the male gametes to the ovule • Topics: ↑botany, ↑phytology • Hypernyms: ↑plant part, ↑plant structure *… …   Useful english dictionary

  • pollen-tube — dulkiadaigis statusas T sritis augalininkystė apibrėžtis Siūliška, mezginės link tįstanti dygstančios žiedadulkės išauga, kuria vyriškosios gametos plaukia prie sėklapradžio. atitikmenys: angl. pollen tube rus. пыльцевая трубка …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • pollen tube — pol′len tube n. bot the tube that forms from a germinating pollen grain and grows toward the ovule, carrying male gametes with it • Etymology: 1825–35 …   From formal English to slang

  • pollen tube — noun Date: 1835 a tube that is formed by a pollen grain and conveys the sperm nuclei to the embryo sac of an angiosperm or the archegonium of a gymnosperm …   New Collegiate Dictionary

  • pollen tube — Bot. the protoplasmic tube that is extruded from a germinating pollen grain and grows toward the ovule. [1825 35] * * * …   Universalium

  • pollen tube — noun the tube that develops from the wall of a pollen grain and, in seed plants, provides a passage through which the male nuclei reach the embryo sac to effect fertilization …   Wiktionary

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