| 释义 |
pentamerous, a.|pɛnˈtæmərəs|
[f. penta- + Gr. µέρος part + -ous.]
Having, consisting of, or characterized by, five parts or divisions.
1. Bot. Having the parts of the flower-whorl five in number. (Often written 5-merous.).
1835Lindley Introd. Bot. (1848) I. 316 Pentamerous, if a flower consists of organs in fives. 1857Henfrey Elem. Bot. 222 Trees or shrubs with..an imbricated 5-merous calyx and corolla. 1879Bennett in Academy 11 Jan. 33/2 The four stamens of Scrophulariaceae and Labiatae are admitted to result from a degradation from the pentamerous type.
2. Zool.
a. Consisting of five joints, as the tarsi of certain insects; also applied to such insects themselves, as the beetles of the group Pentamera.
b. Having five radiating parts or organs, as a star-fish or other echinoderm.
1826Kirby & Sp. Entomol. III. xxxv. 683 Pentamerous insects are those which have five joints in all their tarsi. 1828Ibid. IV. xlvii. 376 Tarsi pentamerous. 1870Rolleston Anim. Life Introd. 143 Echinodermata. Animals..which..combine with a radial and, ordinarily, pentamerous arrangement, traces of a bilateral symmetry.
So penˈtameral a. = prec.; penˈtameran, a pentamerous beetle (see 2 a, above); ˈpentamere |-mɪə(r)|, each of the five divisions of a pentamerous animal; penˈtamerism, the condition or character of being pentamerous; penˈtameroid a., allied to the extinct genus Pentamerus, of the family Pentameridæ of brachiopods, having somewhat pentagonal shells; n. a brachiopod of this family.
1842Brande Dict. Sci. etc., Pentamerans, Pentamera..a section of Coleopterous insects, including those which have five joints on the tarsus of each leg. 1899Nature 14 Sept. 460/1 Theories of stalked-ancestry, pentameral symmetry, and the like. 1900Lankester Treat. Zool. iii. 19 Variation from pentamerism may arise suddenly (discontinuous meristic variation). Ibid. 99 The whole animal can be divided into 5 corresponding and almost symmetrical sections, ‘pentameres’, by 5 imaginary ‘perradial planes’. |