View source for Striga ← Striga You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=Striga |accepted_authority=Loureiro |publications={{Treatment/Publication |title=Fl. Cochinch. |place=1: 22. 1790 |year=1790 }} |common_names=Witchweed |special_status={{Treatment/ID/Special_status |code=I |label=Introduced }} |basionyms= |synonyms= |hierarchy=Orobanchaceae;Striga |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Orobanchaceae]]</div><div class="higher-taxon"><small>genus</small>[[Striga]]</div></div> |etymology=Latin strigosus, slender, alluding to habit |volume=Volume 17 |mention_page=page 457 |treatment_page=page 508 }}<!-- --><span class="statement" id="st-undefined" data-properties=""><b>Herbs,</b> annual; chlorophyllous or achlorophyllous, hemiparasitic or holoparasitic, haustoria either single and relatively large, or multiple, smaller, and formed on secondary roots. <b>Stems</b> erect, sometimes fleshy, hispid, puberulent, or glabrous. <b>Leaves</b> cauline, opposite, subopposite, or alternate; petiole absent; blade not fleshy, not leathery, margins entire. <b>Inflorescences</b> terminal, racemes or spikes; bracts present. <b>Pedicels</b> present or absent; bracteoles present. <b>Flowers</b>: sepals 5(–8), calyx radially or bilaterally symmetric, tubular, lobes lanceolate or subulate; petals 5, corolla red, brownish red, or purple, rarely white or yellow, bilabiate, salverform, abaxial lobes 3, adaxial 2; stamens 4, didynamous, filaments glabrous; staminode 0; ovary 2-locular, placentation axile; stigma capitate. <b>Capsules</b>: dehiscence loculicidal. <b>Seeds</b> 400–600, brown or black, ovoid, wings absent.</span><!-- -->{{Treatment/Body |distribution=s Asia;Africa;Australia. |introduced=true |discussion=<p>Species ca. 40 (2 in the flora).</p><!-- --><p><i>Striga</i> produces leaves of different sizes; typical proximal leaves are scalelike, and mid-stem leaves are larger. <i>Striga</i> is distinguished from its close relative <i>Buchnera</i> by its bilabiate corolla with an abruptly bent tube, one pollen sac, and glabrous filaments. <i>Buchnera</i> has a bilabiate corolla with a straight or slightly curved tube, two pollen sacs, and pilose filaments. <i>Striga</i> has been divided into three sections based on the number of ribs on the calyx tube (R. Wettstein 1891–1893): sect. Pentapleurae Wettstein with five, sect. Polypleurae Wettstein with ten, and sect. Tetrasepalum Engler with 15.</p><!-- --><p>Thirty-four species and subspecies of witchweeds occur in Africa; 22 are endemic (K. I. Mohamed et al. 2001). All <i>Striga</i> species parasitize hosts in the <i>Poaceae</i> except <i>S. gesnerioides</i>, which grows on hosts in Acanthaceae, Convolvulaceae, Euphorbiaceae, Fabaceae, and Solanaceae. <i>Striga asiatica</i>, S. aspera Bentham, S. forbesii Bentham, <i>S. gesnerioides</i>, and S. hermonthica (Delile) Bentham are of economic importance. Crops most affected by <i>Striga</i> include <i>Digitaria</i> exilis (fonio), <i>Oryza</i> subspp. (upland rice), <i>Pennisetum glaucum</i> (bulrush millet), <i>Sorghum</i> vulgare (sorghum), and <i>Zea mays</i> (maize). <i>Striga gesnerioides</i> is a serious pest on Vigna unguiculata (cowpea, Fabaceae) and a minor pest on other dicot crops. All species of witchweed are listed as noxious weeds by the United States Department of Agriculture and 11 state governments. New infestations of quarantine pests in the United States, such as witchweeds, should be reported to the State Plant Health Director in the appropriate state (http://www.aphis.usda.gov/services/report_pest_disease/report_pest_disease.shtml).</p> |tables= |references= }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Calyx ribs 10; mid-stem leaf blades ascending or spreading, linear or narrowly elliptic, 20–50 mm; bracts linear, longer than calyces; corollas red, rarely yellow, with yellow throats; parasitic on Poaceae. |[[Striga asiatica|Striga asiatica]] |-id=key-0-1 |1 |Calyx ribs 5; mid-stem leaf blades appressed, lanceolate, 3–7 mm; bracts lanceolate, shorter than calyces; corollas brownish red or purple, rarely white; parasitic on dicots. |[[Striga gesnerioides|Striga gesnerioides]] |} </div></div><!-- -->{{#Taxon: name=Striga |author=Kamal I. Mohamed;Lytton J. Musselman |authority=Loureiro |rank=genus |parent rank=family |synonyms= |basionyms= |family=Orobanchaceae |illustrator=Barbara Alongi |illustration copyright=Flora of North America Association |distribution=s Asia;Africa;Australia. |introduced=true |reference=None |publication title=Fl. Cochinch. |publication year=1790 |special status=Introduced |source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V17/V17_878.xml |genus=Striga }}<!-- -->[[Category:Treatment]][[Category:Orobanchaceae]] Templates used on this page: Template:Orobanchaceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/Body/Maps (view source) Template:Treatment/ID (view source) Template:Treatment/ID/Special status (view source) Template:Treatment/Publication (view source) Return to Striga.