https://emsenn.net/tags/angiosperm/ Recent content in Angiosperm on emsenn.net Hugo en-us Thu, 02 Apr 2026 00:00:00 +0000 https://emsenn.net/library/domains/science/domains/biology/domains/botany/terms/polygonaceae/ Thu, 02 Apr 2026 00:00:00 +0000 https://emsenn.net/library/domains/science/domains/biology/domains/botany/terms/polygonaceae/ <p>Polygonaceae (the buckwheat family) is a family of flowering plants in the order Caryophyllales, comprising approximately 1,200 species in 48 genera distributed across all continents except Antarctica. The family includes plants of major economic importance (buckwheat, rhubarb, sorrel), ecological significance (the invasive knotweeds), and pharmaceutical value (<a href="japanese-knotweed.md" class="link-internal">Japanese knotweed</a> as a source of <a href="../../../medicine/domains/pharmacology/terms/resveratrol.md" class="link-internal">resveratrol</a>).</p> <h2 id="the-ochrea-defining-character">The ochrea: defining character</h2> <p>The single most reliable diagnostic feature of Polygonaceae is the <strong>ochrea</strong> (plural: ochreae) — a tubular or funnel-shaped sheath formed from fused stipules that encircles the stem above each node. The ochrea is present in nearly all members of the family (reduced or absent in a few genera of subfamily Eriogonoideae) and is found in no other angiosperm family. When identifying an unknown plant, the presence of an ochrea at the stem nodes is strong evidence for Polygonaceae.</p>