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Pakistan | Family List | Brassicaceae

Isatis Linn., Sp. P1. 670. 1753. Gen.Pl. ed.5: 301.1754; Boiss., l.c. 376; Schulz in Engl.&Prantl, l.c. 420 ;Busch in Kom., l.c. 203 ;Avetisian, V. in Not. Syst. Tbil. 23:72. 1963 ; Davis, l.c. 287; Hedge in Rech.f., l.c.77.

Isatis minima

Credit: Azmat

  • Pachypteris Kar. et Kir.
  • Pachypterygium Bunge

    Annual, biennial or perennial herbs, branched, usually glabrous and glau¬cous except the siliculae. Basal leaves usually elliptic-oblong, stalked to sessile; cauline leaves sessile, cordate or sagittate to ovate-oblong, amplexicaul, usually entire. Inflorescence racemose, branched or panicled, ebracteate, often becom¬ing lax and elongated in fruit. Flowers small, yellow to whitish or lilac-white; pedicel filiform, often deflexed in fruit. Sepals suberect, almost equal, not saccate at the base. Petals slightly to c. twice as long as the sepals, oblong-obovate with rounded apex. Stamens 6; filaments not appendaged; anthers minute. Lateral nectar glands almost annular, often subsinuate towards the inner side; middle narrow, joining the laterals. Ovary oblong, elliptic or ovate, flattened, unilocular with 1-2 pendulous ovules; stigma almost sessible, sub-bibbed. Siliculae usually linear, oblong-cuneate to suborbicular, indehiscent, laterally flattened, unilocular, slightly to conspicuously winged, glabrous or minutely hairy, rarely papillose; apex usually truncate or sub-retuse; locule walls usually with a distinct mad-vein; septum absent; seed usually 1, oblong, brownish; radicle accumbent or incumbent.

    About 50 species, chiefly in Irano-Turanian region. A difficult genus due to extremely variable nature of its many species. Only 7 species occur in our area.

    The single character of the very narrow inflated wing (margins) of fruit, which separated Pachypterygium from Isatis does not hold good. Species such as Isatis stocksii Boiss. (Pachypterygium stocksii (Boiss.) Hedge; Pachypterygium macranthum Rech.f.), Isatis harsukhii O.E. Schulz (Pachypterygium leptoloma Rech.f.; Pachypterygium afghanicum Gilli), Isatis emarginata Kar. et Kir. and the enitre section Glastum DC. of Isatis (with species having somewhat narrow thickened wings of fruit) have intermediate characters of the wings and may be placed in either of these two genera. Therefore, Pachypterygium Bunge has been merged in Isatis L. The 2 species transferred from Pachypterygium to Isatis, will fall under the section, Eremoglaston Bunge, with Isatis stocksii and Isatis emarginata, due to their non spongy locules. The rest of the species of Isatis have spongy locules and fall under other sections.

    1 Siliculae oblong-linear, narrowed towards the base, conspicuously winged towards the apex only   (7)
    + Siliculae broadly elliptic or somewhat lamp-shaped, narrowly to broadly winged all around   (2)
    2 (1) Siliculae somewhat lamp-shaped, longer than broad   (3)
    + Siliculae ± broadly elliptic   (5)
    3 (2) Siliculae curved upwards; neck longer than the body or locule   Isatis stocksii
    + Siliculae flattened, not curved; neck usually shorter than the body   (4)
    4 (3) Siliculae large, c.10 x 5 mm   Isatis emarginata
    + Siliculae small, c. 4 x 2 mm   Isatis brevipes
    5 (2) Siliculae more than 10 mm long; wings more than 3 mm broad, not thickened, membranous, broader than locule; locule well transversely corrugated or wrinkled when mature   Isatis latisiliqua
    + Siliculae less than 7 mm long; wings not more than 1 mm broad, slightly to distinctly thickened, narrower than locule; locule wall smooth   (6)
    6 (5) Siliculae 5-7 mm long, 3-5 mm broad; wings slightly or not thickened; flowers c.4 mm across; petals c.4 mm long   Isatis harsukhii
    + Siliculae 2-3 mm long, c.2 mm broad; wings thickened; flowers c. 2 mm across; petals c.2 mm long   Isatis multicaulis
    7 (1) Apical portion of wing shorter than the locule length; apex of silicula conspicuously rounded   Isatis costata
    + Apical portion of wing usually longer than the locule length; apex of siliculae + truncate or subrounded   (8)
    8 (7) Locule about as long or little shorter than the apical portion of the wing; siliculae apex usually sub-bilobed (truncate-emargnate); plants usually fruiting down to the base   Isatis minima
    + Locule much shorter than the apical portion of the wing; siliculae apex ± rounded to subtruncate; plants fruiting above only   Isatis tinctoria

  • List of lower taxa


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