Phylogenetic approaches resolve taxonomical confusion in <i>Pedicularis</i> (Orobanchaceae): Reinstatement of <i>Pedicularis delavayi</i> and discovering a new species <i>Pedicularis milliana</i>

<div><p>Morphological identification of <i>Pedicularis</i> depends on floral characters. However, some important characters may be lost during the process of pressing the specimen. <i>Pedicularis delavayi</i> was described from northwestern Yunnan, and widely adopted as a variety of <i>P</i>. <i>siphonantha</i>. Unfortunately, the name “<i>P</i>. <i>siphonantha</i> var. <i>delavayi</i>’ incorrectly referred to <i>P</i>. <i>milliana</i> (a new species described in this study) or <i>P</i>. <i>tenuituba</i> in some herbarium specimens and publications. Moreover, phylogenetic relationships among <i>P</i>. <i>delavayi</i>, <i>P</i>. <i>siphonantha</i> and its allies (<i>P</i>. <i>milliana</i> and <i>P</i>. <i>tenuituba</i>) were not fully resolved. In this study, we sampled 76 individuals representing 56 taxa. Of them, 10 taxa were from <i>P</i>. <i>siphonantha</i> lineage, and 11 individuals of <i>P</i>. <i>delavayi</i> represented 9 populations. These species were named as <i>P</i>. <i>siphonantha</i> group on the basis of morphological similarity. Nuclear ribosomal internal transcribed spacer (nrITS) and four chloroplast genes/regions were used for phylogenetic analyses. Phylogenetic analyses showed that the <i>P</i>. <i>siphonantha</i> group was polyphyletic: <i>P</i>. <i>delavayi</i> was sister to <i>P</i>. <i>obliquigaleata</i> in clade A; and the remaining species of <i>P</i>. <i>siphonantha</i> group were monophyletic in clade B, named as <i>P</i>. <i>siphonantha</i> lineage. In the <i>P</i>. <i>siphonantha</i> lineage, <i>P</i>. <i>milliana</i>, <i>P</i>. <i>siphonantha</i>, and <i>P</i>. <i>tenuituba</i> were well supported as monophyletic, and <i>P</i>. <i>dolichosiphon</i> was sister to <i>P</i>. <i>leptosiphon</i>. Morphologically, <i>P</i>. <i>delavayi</i> differs from species of the <i>P</i>. <i>siphonantha</i> lineage in having a long petiole (~ 50 mm) and pedicel (~ 40 mm), a ridged corolla tube, and a folded lower-lip of the corolla. Therefore, both morphological characters and phylogenetic evidence strongly supported to reinstate <i>P</i>. <i>delavayi</i> as an independent species and describe <i>P</i>. <i>milliana</i> as new species. In addition, <i>P</i>. <i>neolatituba</i> was proposed to reduce as a new synonymy of <i>P</i>. <i>delavayi</i>.</p></div

Sequence characteristics of nrITS and four plastid DNA regions.

<p>Sequence characteristics of nrITS and four plastid DNA regions.</p

Phylogeny of the <i>Pedicularis siphonantha</i> group inferred from Bayesian Inference (BI) and Maximum Likelihood (ML) methods using the combination of nuclear ribosomal internal transcribed spacer (nrITS) and four plastid (<i>matK</i>, <i>rbcL trnH-psbA</i> and <i>trnL-F</i>) datasets.

<p>Topology shows the majority rule consensus of the BI tree. BI posterior probability (PP) ≥ 0.50 and ML bootstrap support (BS) ≥ 50 were annotated on the branch. PP ≥ 0.95 and/or BS ≥ 70 were drawn with thicker and black lines.</p

Field photos of <i>P</i>. <i>delavayi</i> Franch. ex Maxim., <i>P</i>. <i>milliana</i> W. B. Yu, D. Z. Li & H. Wang and <i>P</i>. <i>siphonantha</i> D. Don.

<p>A, <i>P</i>. <i>siphonantha</i>. B, <i>P</i>. <i>milliana</i>. C-I, <i>P</i>. <i>delavayi</i>: C, G-I, from Daxue Mtn.; D from Hong Mtn.; E from Yulong Mtn.; F from Wuxu Lake. A spreading middle lobe of the corolla lower-lip with emargination indicated by an arrow in A and B; a folded middle lobe of the corolla lower-lip with emargination indicated by an arrow in D-G; a ridged corolla tube indicated by an arrow in G and H; an inflated calyx tube in the middle upper parts indicated by an arrow in H; black seeds indicated by an arrow in I. A and B were taken by Z.-K. Wu; E by H.-D. Li; C, D, and F-I by W.-B. Yu.</p