1. Family: Poaceae Barnhart
    1. Tristachya Nees

      1. This genus is accepted, and its native range is Tropical & S. Africa, Madagascar, Mexico to Central America, Brazil to Paraguay.

    [FZ]

    Gramineae, W. D. Clayton. Flora Zambesiaca 10:3. 1989

    Inflorescences
    Panicle open or contracted (T. thollonii racemose), sometimes bearing the spikelets in groups of 2 or 3 on long unequal pedicels, but more often bearing them in triads whose pedicels are usually connate.
    Spikelets
    Spikelets narrowly lanceolate (except T. viridiaristata), brown, often large, disarticulating beneath each floret.
    Lemma
    Inferior lemma 5–7-nerved. Superior lemma usually pubescent, rarely with 2 or more tufts of hair, bilobed, geniculately awned, the awn usually deciduous; callus conical, pungent (T. huillensis linear and bluntly pointed); palea keels thickened but not winged.
    [FTEA]

    Gramineae, W. D. Clayton, S. M. Phillips And S. A. Renvoize. Flora of Tropical East Africa. 1974

    Habit
    Perennials, rarely annuals, erect
    Leaves
    Leaf-blades linear, usually flat, not crinkled on the margin; ligule a ciliate fringe
    Inflorescences
    Inflorescence a panicle, open or contracted (triads subsessile in T. thollonii),the spikelets ternate (paired in T. hubbardiana) and often with the pedicels connate thus mimicking a single spikelet
    Spikelets
    Spikelets large, brown to straw-coloured, disarticulating beneath each floret, the lower floret ♂; glumes typically lanceolate, chartaceous to coriaceous, 3-nerved, ± persistent, the upper as long as the spikelet, the lower usually shorter; lower lemma 5-nerved, similar to the upper glume but usually a little shorter; upper lemma oblong-elliptic, thinly coriaceous, usually pubescent, 5–9-nerved, bilobed, sometimes the lobes aristulate and rarely with a tuft of hairs at their base, with a deciduous (except T. bicrinita) geniculate awn from the sinus; callus conical, pungent, pubescent; palea-keels usually with thickened nerves, wingless; stamens 3
    Fruits
    Caryopsis linear, the hilum linear.
    [GB]

    nonem

    Habit
    Annual (1), or perennial (20). Rhizomes absent (15), or short (4), or elongated (2). Culms erect (20), or geniculately ascending (1), or decumbent (1); 20-97.2-270 cm long. Lateral branches lacking (5/6), or sparse (2/6). Ligule a fringe of hairs. Leaf-blades filiform (3), or linear (18); herbaceous (19), or coriaceous (2); stiff (4), or firm (17). Leaf-blade margins cartilaginous (1/1).
    Inflorescences
    Inflorescence a panicle (20), or composed of racemes (1); exserted (20), or embraced at base by subtending leaf (1). Panicle open (14/19), or contracted (6/19). Primary panicle branches not whorled (20/20), or whorled at lower nodes (1/20). Racemes single (1/1); bilateral (1/1); bearing few fertile spikelets (1/1); bearing 3-24 fertile spikelets on each (1/1). Rhachis angular (1/1). Spikelets appressed (1/1); in pairs (3), or in threes (20). Fertile spikelets pedicelled; 2 in the cluster (3), or 3 in the cluster (20); subequal (2/2). Pedicels free (8), or fused to each other (13); filiform (3/3), or linear (1/3).
    Spikelets
    Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; of unremarkable solid shape (20), or turbinate (1); laterally compressed; 8-22.92-45 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pubescent (14/20), or pilose (1/20), or bearded (5/20); acute (1), or pungent.
    Fertile
    Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; of unremarkable solid shape (20), or turbinate (1); laterally compressed; 8-22.92-45 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pubescent (14/20), or pilose (1/20), or bearded (5/20); acute (1), or pungent.
    Glume
    Glumes persistent; shorter than spikelet (3), or reaching apex of florets (1), or exceeding apex of florets (18). Lower glume lanceolate (17), or elliptic (3), or ovate (1); chartaceous (19), or coriaceous (2); without keels; 3 -veined. Lower glume surface smooth, or asperulous (1); glabrous (14), or pilose (2), or hispidulous (1), or setose (9). Lower glume apex acute (14), or acuminate (6), or attenuate (3), or setaceously attenuate (3). Upper glume lanceolate; chartaceous; without keels; 3 -veined. Upper glume surface glabrous, or setose (1); with tubercle-based hairs (1/1). Upper glume apex entire, or dentate (1); 2 -fid (1/1); obtuse (8/20), or acute (10/20), or acuminate (3/20), or attenuate (1/20).
    Florets
    Basal sterile florets male, or barren (1); with palea. Lemma of lower sterile floret lanceolate; chartaceous; 3 -veined (1/20), or 5-7 -veined (19/20); acute (19), or acuminate (3). Fertile lemma elliptic (1), or oblong (20); coriaceous; without keel; 5 -veined (1/15), or 7 -veined (11/15), or 9 -veined (3/15). Lemma surface glabrous (4), or pubescent (15), or pilose (2); hairy on back (16/17), or in lines (1/17); without hair tufts (18), or with a transverse row of hair tufts (3). Lemma margins involute; interlocking with palea keels. Lemma apex dentate (2), or lobed (19); 2 -fid; incised 0.2-0.2643-0.4 of lemma length; acute (3/4), or setaceously attenuate (1/4); awned; 1 -awned (11), or 3 -awned (10). Principal lemma awn from a sinus; geniculate. Lateral lemma awns shorter than principal (6/6). Palea membranous (20), or coriaceous (1); 2 -veined. Palea keels approximate; unthickened (2), or thickened (19); wingless (13), or winged (8). Palea surface glabrous (18), or pubescent (3).
    Flowers
    Anthers 3 (20/20). Ovary glabrous (3/14), or pubescent on apex (11/14).
    Fruits
    Caryopsis with adherent pericarp (20/20); linear (2/2). Hilum linear (2/2).
    Distribution
    Africa (17), or North America (3), or South America (2).

    Images

    Distribution

    Native to:

    Angola, Benin, Botswana, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Burkina, Burundi, Cameroon, Cape Provinces, Caprivi Strip, Central African Repu, Chad, Congo, El Salvador, Free State, Gabon, Ghana, Guatemala, Honduras, Ivory Coast, KwaZulu-Natal, Lesotho, Madagascar, Malawi, Mali, Mexico Central, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Mozambique, Namibia, Nicaragua, Nigeria, Northern Provinces, Paraguay, Senegal, Sudan, Swaziland, Tanzania, Uganda, Zambia, Zaïre, Zimbabwe

    Tristachya Nees appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Irwin, H.S. [7337], Brazil K001106063

    First published in C.F.P.von Martius, Fl. Bras. Enum. Pl. 2: 458 (1829)

    Accepted by

    • Govaerts, R.H.A. (2011). World checklist of selected plant families published update Facilitated by the Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Flora of West Tropical Africa
    • Clayton in Kew Bull. 21: 120 (1967).
    • Phipps in Kirkia 4: 101 (1964)
    • Conert in Engl., Bot. Jahrb. 77: 296 (1957)
    • F.T.A. 10: 52 (1937)
    • C. E. Hubbard in Kew Bull. 1936: 321
    • Agrost. Bras. 458 (1829)
    Flora Zambesiaca
    • Agrost. Bras.: 458 (1829).
    Flora of Tropical East Africa
    • Clayton in K.B. 21: 120 (1967)
    • Phipps in Kirkia 5: 249 (1966)
    • Phipps in Kirkia 4: 101 (1964)
    • Conert in E.J. 77: 296 (1957)
    • Hubbard in K.B. 1936: 321 (1936)
    • Agrost. Bras.: 458 (1829)

    Sources

    Flora Zambesiaca
    Flora Zambesiaca
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    GrassBase - The Online World Grass Flora
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0