SYSTEMATICS OF THE DELESSERIACEAE (CERAMIALES, RHODOPHYTA) BASED ON LARGE SUBUNIT rDNA AND <i>rbc</i>L SEQUENCES, INCLUDING THE PHYCODRYOIDEAE, SUBFAM. NOV.

<jats:p>The present classification of the Delesseriaceae retains the essential features of Kylin's system, which recognizes two subfamilies Delesserioideae and Nitophylloideae and a series of “groups” or tribes. In this study we test the Kylin system based on phylogenetic parsimony and distance analyses inferred from two molecular data sets and morphological evidence. A set of 72 delesseriacean and 7 additional taxa in the order Ceramiales was sequenced in the large subunit rDNA and <jats:italic>rbc</jats:italic>L analyses. Three large clades were identified in both the separate and combined data sets, one of which corresponds to the Delesserioideae, one to a narrowly circumscribed Nitophylloideae, and one to the Phycodryoideae, subfam. nov., comprising the remainder of the Nitophylloideae sensu Kylin. Two additional trees inferred from <jats:italic>rbc</jats:italic>L sequences are included to provide broader coverage of relationships among some Delesserioideae and Phycodryoideae. Belonging to the Delesserioideae are the Caloglosseae with <jats:italic>Caloglossa;</jats:italic> an expanded Hemineureae that includes <jats:italic>Hemineura</jats:italic>, <jats:italic>Patulophycus</jats:italic>, <jats:italic>Marionella</jats:italic>, <jats:italic>Laingia</jats:italic>, <jats:italic>Botryocarpa</jats:italic>, and <jats:italic>Pseudophycodrys;</jats:italic> the Delesserieae with <jats:italic>Delesseria</jats:italic> and <jats:italic>Membranoptera;</jats:italic> the Apoglosseae with <jats:italic>Apoglossum</jats:italic> and a group of southern hemisphere species presently placed in <jats:italic>Delesseria</jats:italic> that belong in <jats:italic>Paraglossum;</jats:italic> the Hypoglosseae with <jats:italic>Hypoglossum</jats:italic>, <jats:italic>Branchioglossum</jats:italic>, <jats:italic>Zellera</jats:italic>, and <jats:italic>Bartoniella;</jats:italic> and the Grinnellieae with <jats:italic>Grinnellia.</jats:italic> The revised Nitophylloideae contains the Nitophylleae with <jats:italic>Nitophyllum</jats:italic>, <jats:italic>Valeriemaya</jats:italic>, <jats:italic>Polyneuropsis</jats:italic>, and <jats:italic>Calonitophyllum</jats:italic> and the Martensieae with <jats:italic>Opephyllum</jats:italic> and <jats:italic>Martensia.</jats:italic> A new subfamily, Phycodryoideae, is proposed to include the Phycodryeae with <jats:italic>Phycodrys</jats:italic>, <jats:italic>Polyneura</jats:italic>, <jats:italic>Nienburgia</jats:italic>, <jats:italic>Cladodonta</jats:italic>, <jats:italic>Heterodoxia</jats:italic>, and <jats:italic>Womersleya;</jats:italic> the Cryptopleureae with <jats:italic>Cryptopleura</jats:italic>, <jats:italic>Hymenena</jats:italic>, <jats:italic>Acrosorium</jats:italic>, and <jats:italic>Botryoglossum;</jats:italic> the Myriogrammeae with <jats:italic>Myriogramme</jats:italic> and <jats:italic>Haraldiophyllum;</jats:italic> and the Schizoserideae with <jats:italic>Schizoseris</jats:italic>, <jats:italic>Neuroglossum</jats:italic>, <jats:italic>Drachiella</jats:italic>, <jats:italic>Abroteia</jats:italic>, and species from South America placed in <jats:italic>Platyclinia.</jats:italic> This research promotes the correlation of molecular and morphological phylogenies.</jats:p>