Tristachya Nees
  • C.F.P.von Martius, Fl. Bras. Enum. Pl. 2: 458 (1829) 


General Description

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). INFLORESCENCE 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). FERTILE 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. GLUMES 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). FLOWER Anthers 3 (20/20). Ovary glabrous (3/14), or pubescent on apex (11/14). FRUIT Caryopsis with adherent pericarp (20/20); linear (2/2). Hilum linear (2/2). DISTRIBUTION Africa (17), or North America (3), or South America (2).

  Bibliography

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

 Information From

GrassBase - The Online World Grass Flora
http://www.kew.org/data/grasses-db/
Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. http://www.kew.org/data/grasses-db.html. [accessed 24 January 2012; 14:30 GMT]
  • A © Copyright The Board of Trustees, Royal Botanic Gardens, Kew.
eMonocot
http://e-monocot.org
eMonocot. (2010, 1st November). Retrieved Wednesday, 8th February, 2012, from http://e-monocot.org.
  • B Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
World Checklist of Selected Plant Families
http://apps.kew.org/wcsp/
WCSP 2014. 'World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://apps.kew.org/wcsp/ Retrieved 2011 onwards
  • C See http://kew.org/about-kew/website-information/legal-notices/index.htm You may use data on these Terms and Conditions and on further condition that: The data is not used for commercial purposes; You may copy and retain data solely for scholarly, educational or research purposes; You may not publish our data, except for small extracts provided for illustrative purposes and duly acknowledged; You acknowledge the source of the data by the words "With the permission of the Trustees of the Royal Botanic Gardens, Kew" in a position which is reasonably prominent in view of your use of the data; Any other use of data or any other content from this website may only be made with our prior written agreement.