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Pakistan | Family List | Poaceae

Elymus Linn., Sp. Pl. 1:83. 1753. Gen. Pl., ed. 5. 36. 1754; Tzvelev, Poaceae URSS 106. 1976; Melderis in Tutin et al., Fl. Eur. 5:192. 1980.

  • Agropyron*
  • Anthosachne Steud.
  • Clinelymus (Griseb.) Nevski
  • Elymus sect. Clinelymus Griseb.
  • Elytrigia Desv.
  • Roegneria C. Koch

    Tufted or rhizomatous perennials. Leaf-blades flat or convolute. Inflorescence a spike. Spikelets 2-11-flowered, sessile or very shortly pedicelled, imbricate, solitary or in groups of 2-3 at the nodes of the tough rhachis; rhachilla disarticulating above the glumes and between the florets, or sometimes the spikelets falling entire; glumes 1-11-nerved, awned or awnless, rounded on the back or sometimes keeled towards the tip; lemmas 5-nerved, awned or awnless; palea 2-keeled.

    A genus of about 100 species in temperate regions of the northern hemisphere; 20 species occur in Pakistan, 1 of them with an introduced subspecies.

    At one time the genus consisted only of those species with more than 1 spikelet at each inflorescence node, but with recent changes in generic concepts in the tribe it now includes those species of Agropyron without keeled glumes. Further-more, species formerly included in Elymus having narrow glumes covering the sides of the lower florets have been transferred to Leymus.

    The following hyrides have been reported from Pakistan. They are generally intermediate between their putative parents and some of them are sterile. None has yet been thoroughly investigated cytologically and experimentally to confirm its origin.

    Elymus cognatus x dasystachys (x Agroelymus pamiricus (Meld.) Meld.)

    Elymus cognatus x nutans (x Agroelymus koelzii Meld.)

    Elymus dentatusy x fedtschenkoi (Agropyron x nothum Meld.)

    Elymus dentatus x russellii (Agropyron x spurium Meld.)

    Elymus fedtschenkoi x longe-aristatus subsp. canaliculatus (Agropyron x interjacens Meld.)

    1 Spikelets in groups of 2-3 in the middle part of the rhachis   (2)
    + Spikelets solitary at all nodes of the rhachis   (3)
    2 (1) Glumes almost as long to as long as the lowest lemma (awns excluded)   Elymus dahuricus
    + Glumes much shorter than the lowest lemma (awns excluded)   Elymus nutans
    3 (1) Lemma with an awn at least as long as itself   (4)
    + Lemma awnless or with a short awn not as long as the body of the lemma   (14)
    4 (3) Awn of the lemma straight or slightly flexuous   (5)
    + Awn of the lemma strongly recurved at maturity   (9)
    5 (4) Palea shorter than the lemma, about three quarters as long   Elymus semicostatus
    + Palea as long as or slightly longer than the lemma, rarely slightly shorter but then the glumes abruptly contracted to an awn or awn-like cusp   (6)
    6 (5) Glumes oblong-elliptic, very firm, abruptly contracted at the tip to an awn or awn-like cusp; lemma long-hairy on the margins, glabrous on the back, anthers 4-5.5 mm long   Elymus borianus
    + Glumes and lemmas not as above; anthers 2-3 mm long   (7)
    7 (6) Lemmas entirely glabrous or scabrid only near the tip   (8)
    + Lemmas minutely bristly or puberulous   Elymus russellii
    8 (7) Leaf-sheaths ciliate along the margins; palea-tip rounded or broadly emarginate   Elymus kuramensis
    + Leaf-sheaths glabrous along the margins; paleatip pointed or 2-toothed   Elymus caninus
    9 (4) Glumes almost as long as the lowest lemma (awns excluded)   Elymus fedtschenkoi
    + Glumes considerably shorter than the lowest lemma (awns excluded)   (10)
    10 (9) Rhachilla twisted above the glumes bringing the florets ± dorsiventral to the spike-axis; midrib of lower glume not in line with that of lowest lemma   Elymus schrenkianus
    + Rhachilla not twisted above the glumes; midrib of lower glume in line with that of lowest lemma   (11)
    11 (10) Anthers 1.5-2.5 mm long   (12)
    + Anthers (2.5-) 3-3.5 mm long   Elymus long-earistatus subsp. canaliculatus
    12 (11) Leaf-blades shortly and densely pubescent on both sides, flat or loosely rolled   Elymus schugnanicus
    + Leaf-blades glabrous beneath, pubescent or loosely hairy above, flat, tightly folded or convolute   (13)
    13 (12) Glumes with an awn (2.5-)4-10 mm long; lemma body 11-12.5 mm long   Elymus himalayanus
    + Glumes acuminate or with an awn up to 2 mm long; lemma body 8-9 mm long   Elymus jacquemontii
    14 (3) Plant loosely tufted, with long creeping rhizomes   (15)
    + Plants loosely to densely tufted, without rhizomes   (17)
    15 (14) Anthers 2-25 mm long; glumes usually toothed at the tip, sometimes acuminate or shortly awned; lemma minutely bristly   Elymus dentatus
    + Anthers 3.5-6(-8) mm long, glumes blunt or acuminate; lemma hairy or glabrous   (16)
    16 (15) Glumes acute, mucronate or shortly awned   Elymus repens
    + Glumes obtuse or obliquely truncate   Elymus hispidus
    17 (14) Lemma smooth and glabrous on the back, sometimes the nerves thinly scabrid towards the tip   (18)
    + Lemma scaberulous all over the back; anthers 2-2.5 mm long   Elymus mutabilis
    18 (17) Anthers 2-2.5 mm long; glumes scaberulous on the nerves   Elymus stewartii
    + Anthers 3-5 mm long; glumes quite smooth   (19)
    19 (18) Glumes obtuse or truncate; leaf-sheaths sometimes ciliate along the margins   Elymus nodosus
    + Glumes acute; leaf-sheaths glabrous along the margins   Elymus cognatus

  • List of lower taxa


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