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Pakistan | Family List | Poaceae

Eragrostis Wolf, Gen. Pl. Vocab. Char. Def. 23. 1776. Boiss., Fl. Or. 5:580. 1884; Hook.f., Fl. Brit. Ind. 7:312. 1896; Blatter & McCann, Bombay Grasses 229. 1935; Bor, Fl. Assam 5:93.1940; Sultan & Stewart, Grasses W. Pak. 2:229. 1959; Bor, Grasses Burma Ceyl. Ind. Pak. 495. 1960; Bor in Towns., Guest & Al-Rawi, Fl. Iraq 9: 436. 1968; Bor in Rech.f., Fl. Iran. 70:426. 1970; Tzvelev, Poaceae URSS 630. 1976; Tutin in Tutin et al., Fl. Eur. 5:256.1980.

  • Diandrochloa de Winter
  • Roshevitzia Tzvelev

    Annuals or perennials, often glandular on leaf-sheath and inflorescence (those glands referred to in the key and descriptions may be raised crateriform warts or band-like patches on the inflorescence branches, leaf-sheaths and blades and sometimes the lemmas; other types of gland, much less conspicuous, occur sporadically throughout the genus). Leaf-blades linear; ligule usually reduced to a ciliate rim, rarely membranous. Inflorescence an open, contracted or spike-like panicle, the branches sometimes racemose but at least the longer with short side branchlets, rarely ending in a slender bristle. Spikelets laterally compressed, variously disarticulating, awnless; glumes mostly subequal, shorter than the lowest lemma and 1-nerved; lemmas 3-nerved, mostly glabrous, acuminate to emarginate, rarely mucronulate; palea a little shorter than the lemma, deciduous or persistent, the keels sometimes long-ciliate, rarely winged; anthers 2-3. Caryopsis usually globose to ellipsoid, smooth or finely striate to finely reticulate, the pericarp adherent (sometimes slightly loose but never free).

    A genus of ± 300 species, mainly in the tropics and subtropics, particularly as ruderal and pioneer species; about 14 species are recorded from Pakistan.

    The name Eragrostis is usually ascribed to P. Beauv. (1812), but Ross (in Acta bot. neerl. 15:147-161.1966) argues convincingly that Wolf’s work, despite its eccentricities, constitutes valid publication.

    Eragrostis is a large and very difficult genus to name. No critical subdivision has yet been worked out so the key below relies very heavily on a system that is at least partly artificial. The species are allocated to groups according to the mode of disarticulation of the spikelet. The key is not always easy to use, particularly with species having a mixed mode of abscission, but it can be summarised as follows:

    GROUP I

    Spikelets not breaking up

    1. E. superba

    GROUP II

    Spikelets breaking up from above

    2. E. ciliaris

    3. E. viscosa

    4. E. tenella

    5. E. japonica

    GROUP III

    Spikelets breaking up from below, palea deciduous with the lemma

    6. E. unioloides

    7. E. pilosa

    8. E. atrovirens

    GROUP IV

    Spikelets breaking up from below, palea persistent

    9. E. cilianensis

    10. E. minor

    11. E. barrelieri

    12. E. tremula

    13. E. curvula

    14. E. papposa

    1 Spikelets disarticulating below the glumes at maturity and falling entire   Eragrostis superba
    + Spikelets variously breaking up above the glumes at maturity   (2)
           
    2 (1) Spikelets shedding their florets from the apex downwards at maturity, the rhachilla internodes falling with the florets   (3)
    + Spikelets shedding their florets from below upwards, the rhachilla remaining upon the pedicel (or eventually breaking up)   (6)
           
    3 (2) Palea ciliate on the keels   (4)
    + Palea glabrous on the keels (but usually scabrid or scaberulous)   Eragrostis japonica
           
    4 (3) Lemmas, or at least the upper, with a few short stiff hairs on the keel; panicle woolly, spike-like or ± lobed and interrupted, the spikelets densely clustered; stamens 2   Eragrostis ciliaris
    + Lemmas smooth or slightly scaberulous on the keel; panicles open, neither woolly nor with the spikelets in dense clusters; stamens 3   (5)
           
    5 (4) Inflorescence sticky from glands (not crateriform) on the branchlets and glumes, to which grains of sand adhere   Eragrostis viscosa
    + Inflorescence with or without glands, but not sticky   Eragrostis tenella
           
    6 (2) Palea falling at about the same time as the lemma   (7)
    + Palea persisting on the rhachilla long after the lemma has fallen; sometime the rhachilla early disarticulating above the glumes with most of the florets still attached, or the upper part of the rhachilla becoming fragile after the lower florets have commenced to fall   (9)
           
    7 (6) Spikelets broadly ovate to oblong, 2.5-4 mm wide   Eragrostis unioloides
    + Spikelets narrowly oblong to linear, 0.7-2.5 mm wide   (8)
           
    8 (7) Plant annual; spikelets linear, 0.7-1.2 mm wide   Eragrostis pilosa
    + Plant perennial; spikelets narrowly oblong, 1.5-2.5 mm wide   Eragrostis atrovirens
           
    9 (6) Plant glandular (glands crateriform), at lest on the branchlets and pedicels   (10)
    + Plant eglandular   (12)
           
    10 (9) Grain subglobose, 0.5 mm long   Eragrostis cilianensis
    + Grain oblong or elliptic, 0.65-1 mm long   (11)
           
    11 (10) Leaves with raised crateriform glands along the margin; grain broadly oblong, 0.7-0.8 mm long   Eragrostis minor
    + Leaves eglandular; grain elliptic-oblong, 0.65-1 mm long   Eragrostis barrelieri
           
    12 (9) Plants annual   Eragrostis tremula
    + Plants perennial   (13)
           
    13 (12) Basal leaf-sheaths silky-pubescent below and strongly ridged; lemmas 1.8-2.6 mm long   Eragrostis curvula
    + Basal leaf-sheaths glabrous below; lemmas 1.1-1.7 mm long   Eragrostis papposa

  • List of lower taxa


     

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