Resurrection of Tectaria cadieri from T. ingens (Tectariaceae, Pteridophyta) based on morphological and molecular data

<p>We demonstrate that <em>Tectaria</em> <em>cadieri</em> (Tectariaceae) is a distinct species in Vietnam after long being placed under the synonymy of <em>T. ingens</em>. Morphologically, <em>T. cadieri</em> is similar to <em>T</em>. <em>ingens</em>, <em>T. setulosa</em>, <em>T. trichotoma</em> in their large fronds (up to 0.8–2 m long), 3-pinnate laminae, fully free veins, and sori in two rows on ultimate segments. However, <em>T. cadieri</em> differs from these species in the presence of linear, membranaceous stipe scales. The analyses of five plastid regions (<em>atpB</em>, <em>ndhF</em> plus <em>ndhF</em>-<em>trnN</em>, <em>rbcL</em>, <em>rps16</em>-<em>matK</em> plus <em>matK</em>, and <em>trnL</em>-<em>trnF</em>) also show that <em>T. cadieri</em> is neither closely related to <em>T. ingens</em>, <em>T. setulosa</em>, or <em>T. trichotoma</em>. Rather, <em>T. cadieri</em> is closely related to <em>T. multicaudata</em>, a morphologically distinct species with anastomosing veins. Along with a detailed description and illustrations for <em>T. cadieri</em>, we provided morphological comparisons and comments on the relationships between <em>T. cadieri</em> and morphologically similar species.</p>