View source for Pterostegia

{{Treatment/ID
|accepted_name=Pterostegia
|accepted_authority=Fischer & C. A. Meyer
|publications={{Treatment/Publication
|title=Index Seminum (St. Petersburg)
|place=2: 48. 1836
|year=1836
}}
|common_names=Woodland threadstem
|basionyms=
|synonyms=
|hierarchy=Polygonaceae;Polygonaceae subfam. Eriogonoideae;Pterostegia
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Polygonaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Polygonaceae subfam. Eriogonoideae]]</div><div class="higher-taxon"><small>genus</small>[[Pterostegia]]</div></div>
|etymology=Greek pteron, wing, and stege, covering, alluding to winged bract
|volume=Volume 5
|mention_page=page 219, 222, 475
|treatment_page=page 477
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Herbs,</b> annual; taproot slender. <b>Stems</b> arising directly from the root, sprawling and spreading, solid, not fistulose or disarticulating into ringlike segments, thinly pubescent. <b>Leaves</b> persistent, cauline, opposite; petiole present; blade broadly elliptic to fan-shaped, margins entire or lobed. <b>Inflorescences</b> terminal, cymose, uniparous due to suppression of secondaries distally; branches dichotomous, not brittle or disarticulating into segments, round, thinly pubescent; bracts absent. <b>Peduncles</b> absent. <b>Involucral</b> bracts 1, erect, 2-winged, reticulately veined, lobed or notched, slightly gibbous with age, invaginated adaxial surface hyaline. <b>Flowers</b> 2–3 per involucral cluster; perianth pale yellow to pink or rose, campanulate when open, urceolate when closed, sparsely pubescent abaxially; tepals (5–)6, connate for ca. 1/3 their length, monomorphic, entire apically; stamens 6; filaments adnate to perianth, glabrous; anthers yellow, oval. <b>Achenes</b> included, yellowish brown to brown, winged, globose, glabrous. <b>Seeds</b>: embryo straight. <b>x</b> = 14.</span><!--

-->{{Treatment/Body
|distribution=w United States;nw Mexico.
|discussion=<p>Species 1.</p><!--
--><p><i>Pterostegia</i> and the Baja California, Mexico, endemic Harfordia are the only genera of the tribe Pterostegieae. In both, the involucre is highly modified, becoming a slightly to markedly gibbous, reticulated, winged structure that encloses the mature achene. In <i>Pterostegia</i>, the two wings are slightly enlarged, but in Harfordia the wings are greatly inflated, which apparently aids in achene dispersal.</p>
|tables=
|references={{Treatment/Reference
|id=reveal1989a
|text=Reveal, J. L. 1989c. Remarks on the genus Pterostegia (Polygonaceae: Eriogonoideae). Phytologia 66: 228–235.
}}
}}<!--

--><!--

-->{{#Taxon:
name=Pterostegia
|author=James L. Reveal
|authority=Fischer & C. A. Meyer
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=
|family=Polygonaceae
|distribution=w United States;nw Mexico.
|reference=reveal1989a
|publication title=Index Seminum (St. Petersburg)
|publication year=1836
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V5/V5_1001.xml
|subfamily=Polygonaceae subfam. Eriogonoideae
|genus=Pterostegia
}}<!--

-->[[Category:Treatment]][[Category:Polygonaceae subfam. Eriogonoideae]]