A global phylogeny of Lycopodiaceae (Lycopodiales; lycophytes) with the description of a new genus, Brownseya, from Oceania

Abstract

Lycopodiaceae are one of the oldest lineages of any living vascular plants and contain about 400 species distributed on all continents except Antarctica, with its highest diversity in tropical regions. Previous studies on the morphology, anatomy, and molecular systematics of Lycopodiaceae have made substantial progress in understanding the diversity and evolution of the family, but major issues remain. In particular, earlier studies had relatively sparse taxon sampling, some critical relationships among the genera have not been well resolved, and the monophyly of some genera (e.g., Huperzia, Lycopodiella, Pseudolycopodiella, Spinulum) has not been robustly tested with large sampling. In this study, we apply maximum likelihood, maximum parsimony, and Bayesian inference to a dataset of 1150 (918 newly generated) DNA sequences of seven plastid markers (atpA, psbA‐trnH, rbcL, rps4, rps4‐trnS, trnL, trnL‐F) of 334 accessions representing ca. 155 (ca. 39% of all) species in the family to infer a global phylogeny. Our major results include: (1) the tree is resolved into three primary clades corresponding to the three subfamilies, Huperzioideae, Lycopodioideae, and Lycopodielloideae; (2) these three primary clades are resolved into 17 major clades, of which 16 represent genera recognized in the PPG I classification, while Lycopodiella serpentina is resolved as sister to Palhinhaea, and thus a new genus, Brownseya, is described, and a key to genera of Lycopodielloideae is given; (3) Phylloglossum is strongly or moderately supported as sister to Phlegmariurus in ML and MP analyses (but not in BI analysis), and thus our evidence supports the recognition of Phlegmariurus in order to maintain a monophyletic Huperzia; (4) Lycopodiella is sister to Pseudolycopodiella and they together are sister to Lateristachys + (Brownseya + Palhinhaea); (5) Huperzia, Lycopodiella, Pseudolycopodiella, and Spinulum are each strongly supported as monophyletic; (6) spore morphology is well consistent with the phylogenetic relationships in the family; and (7) based on these results we recognize 17 genera in three subfamilies in the family.

Plastid Phylogenomics and Plastomic Diversity of the Extant Lycophytes

“…The topology of the ML tree was highly consistent with that of the BI tree, except for disagreement on the phylogenetic position of Dendrolycopodium and Lycopodium ( Figure 1 ). Before this study, only a few plastid markers (atpA, psbA-trnH, rbcL, rps4 and rps4-trnS, trnL and trnL-F) or a few species were analyzed in phylogeny studies of Lycopodiaceae [ 8 , 18 , 29 ]. Further phylogenetic work under global and broad sampling and sequencing of Lycopodiaceae and the lycophyte is needed.…”

“…This was followed by divergences among subfamilies of the involved Lycopodiaceae, which were dated to be during the Cretaceous and Jurasic (137 Ma, 95% HPD: 105-177). The crown age of Isoëtaceae is estimated to be 25 Ma (95% HPD: [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34], slightly older than the age estimated by Pereira et al [36]. The diversification of Isoëtaceae appeared recently, with a burst of species diversified in a short period of time, implying a recent evolutionary radiation, and so on in Phlegmariurus and Huperzia in Lycopodiaceae (Figure 5).…”

“…The exponential increase in the speed and accuracy of plastid sequencing has contributed to our understanding of lycophytes. To date, many DNA fragments have been applied to research on lycophytes [ 24 , 25 , 26 , 27 , 28 , 29 ], and since the publication of the first lycophyte plastome of Huperzia lucidula (Michx.) Trevis.…”

Plastome phylogenomic analysis reveals evolutionary divergences of Polypodiales suborder Dennstaedtiineae

“…3 Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan. 4 Museum of New Zealand Te Papa Tongarewa, Cable Street, Wellington 6011, New Zealand. 5 Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai Chenshan Botanical Garden, Shanghai 201602, China.…”

“…Numerous phylogenetic studies have been conducted since the publication of the PPG classification [ 3 ], especially on those globally distributed families, e.g., Lycopodiaceae [ 4 ], Polypodiaceae [ 5 , 6 ], Pteridaceae [ 7 ], and Thelypteridaceae [ 8 , 9 ]. The increase in the number of samples, especially in regions and groups with low sampling density, and the accumulation of molecular data, have improved the ability of taxon delimitation and identification and prompted the publication of some new taxa.…”