The genera of South African plants : arranged according to the natural system / by William Henry Harvey.

  • William H. Harvey
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: The genera of South African plants : arranged according to the natural system / by William Henry Harvey. Source: Wellcome Collection.

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    lateral brandies, successively developed, are usually forked {dichotomous or trichotomous). Sometimes after the first forking the branches are no longer divided, but produce a succession of pedicels on the upper side, forming apparently unilateral racemes; but they differ from true racemes by the pedicels springing, not from the axil of the bract, but from a point opposite its insertion or above or below it. This variety, called a scorpioid cyme, is foimd in Droscra, the Boraginece, and many other plants; when young the branches ai-e frequently rolled back at the top like the tail of a scorpion, whence the name. 63. Bracts arc generally placed singly under each branch of the in- florescence, and imder each pedicel; bracteoles are usually two, one on each side, on the pedicel, or close under the flower, or on the calyx itself; but bracts are also frequently scattered along the floral branches without axillary pedicels. 64. A\nien several bracts are collected in a whorl, or are so close together as to appear whorlcd, or are closely imbricated round the base of a head of flowers or an umbel, they are collectively called an Involucre. The bracts composing an involucre aro variously tci-med, according to thou- ap])earanco, leaves, leaflets, bracts, or scales, when placed close beneath the calyx, they fonn an epicalyx. Balccc, or chafl', of the I'ccoptaclo are the inner scale-like bracts of Composites, grasses, and some other plants, when of a thin, yet rigid substsmee, usually naiTow, and pale or trans- lucent. Qlumes aro the bracts of sedges and grasses. § 9. The Flower. 65. A flower is a terminal bud, enclosing the organs of roproduction by seed. An unopened flower is called a flower-bud, or alabastrum ; and the ])oriod between the opening of a flower and the commencement of \vithoiing is called its authesis. 66. J’he pai-ts of a flower or floral organs aro—1st, the perianth, oon- sisting either wholly of calyx, if in a single whorl; or of calyx and corolla, if in a iloublo whorl; 2nd, tho stamens, or fertilizing organs; 3rd, tlio pistil, which contiiins the ovules, or gonns of the future seed. 67. A complete flower is one in which tho calyx, coiolla, stamens, and pistil aro all present; a perfect flower is one in wliich all these organs, or such of them as aro present, aro cajiablo of performing their several func- tions. An incomplete flower is one in which some of the floral organs aro wanting ; and an imperfect flower one in which some organs arc so altered as to bo incai)able of performing their proper functions. Imperfect organs arc said to be suppressed, abortive, or rudimentary, if very much reduced in size and almost obliterated. 68. A flower is, dichlamydcous, when tho perianth is in two distinct whorls. monochiamydemis, when tho peiianth is in one whorl, or when calyx and corolla arc so consolidated as to appear in a single piece. asepalous, when there is no calyx. apetalous, when there is no corolla. naked, when there is no perianth. hermaphrodite, or bisexual, when both stamens and pistil aro present and perfect. male, or staminate, when stamens, but no pistil, or only an imperfect one, ai’o present. female, or pistillate, when there is a perfect pistil, but no stamens, or only imp)crfcct ones, ])rcsent. neuter, when both stamens and pistils are imperfect or absent.