Morinaceae

Introduction

An excellent taxonomic revision of Morinaceae was published by Cannon and Cannon in 1984. They recognized 13 species extending from south-eastern Europe and Israel to the Himalayas of Nepal, Bhutan, and China, and further east and north in the Qinghai-Tibetan Plateau. These plants most often grow at high elevations, sometimes in excess of 4,200 meters, but they occupy a range of habitats, including rock ledges, alpine meadows, dry slopes, the margins of pine forests, and even swamps.

Characteristics

Within Morinaceae, Cannon & Cannon (1984) recognized three genera: Morina, Acanthocalyx, and Cryptothladia. Acanthocalyx has basal, opposite leaves, corolla lobes that are more or less equal in size, four fertile stamens, and pollen grains that lack prominent protrusions. In contrast, Morina and Cryptothladia share whorled leaves, distinctly zygomorphyic, 2-lipped corollas with unequal lobes, two fertile stamens and two reduced sterile stamens, and a unique pollen form with three prominent equatorial protrusions (Blackmore & Cannon, 1983; Cannon & Cannon, 1984). Cryptothladia differs from Morina in having 2-4 corolla lobes as opposed to five, and in that the corolla is equal to or, in most cases, shorter than the calyx. Cryptothladia flowers appear to be predominantly cleistogamous.

Cannon & Cannon (1984) compared Morinaceae to Valerianaceae and Dipsacaceae, but did not specifically hypothesize relationships among these groups. Morinaceae have sometimes been united with Dipsacaceae, and in some treatments are even considered to be a tribe within Dipsacaceae (e.g., Cronquist, 1988). Such treatments highlight the presence of a distinctive epicalyx surrounding the ovary in these groups plus Triplostegia (which has a double epicalyx). Other authors have highlighted similarities shared by Morinaceae, Valerianaceae, and Triplostegia, such as the presence of three distinct carpels (two of which abort), and of clearly zygomorphic corollas. Backlund & Bremer (1998) summarized the varying taxonomic treatments of the group.

Relationships of Morinaceae to Other Dipsacales

In recent years a variety of phylogenetic analyses have supported the monophyly of the Morinaceae and clarified its relationships within Dipsacales (Caputo & Cozzolino, 1994; Peng et al., 1995; Backlund & Donoghue, 1996; Backlund & Bremer, 1997; Bell et al., 2001; Donoghue et al., 2001; Pyck, 2001; Pyck et al., 2002; Donoghue et al., in press; Zhang et al., in press). The more recent and most comprehensive of these analyses have agreed that Morinaceae, Valerianaceae, Triplosetgia, and Dipsacaceae form a clade (the Valerina clade of Donoghue et al. 2001), and that this is in turn united with the Linnaeeae of the traditional Caprifoliaceae (together forming the Linnina clade of Donoghue et al., 2001). Within Valerina there have been some differences among phylogenetic analyses, although these have been weakly supported. Several analyses combining different data sources have supported the hypothesis that Morinaceae form the sister group of a clade containing Valerianaceae plus a clade containing Dipsacaceae plus Triplostegia.

Discussion of Phylogenetic Relationships

Representatives of the three genera of Morinaceae have been included in several previous phylogenetic studies (Caputo & Cozzolino, 1994; Peng et al., 1995; Backlund & Donoghue, 1996; Bell et al., 2001; Donoghue et al., 2001; Pyck, 2001; Donoghue et al., in press). In all of these cases, Acanthocalyx has been found to be the sister group of Morina plus Cryptothladia. However, only one species has been included from each of these groups, and it has therefore not been possible to test their monophyly.

References

Backlund, A. A. & Bremer, K. (1997): Phylogeny of the Asteridae s. str. based on rbcL sequences, with particular reference to the Dipsacales. Pl. Syst. Evol. 207:225-254.

Backlund, A. A. & Bremer, K. (1998): To be or not to be- principles of classification and monotypic plant families. Taxon 47:391-400.

Backlund, A. A. & Donoghue, M. J. (1996): Morphology and phylogeny of the order Dipsacales. In Phylogeny of the Dipsacales, A. A. Backlund, Doctoral Dissertation. Uppsala: Department of Systematic Botany, Uppsala Univ.

Backlund A. A. & Pyck, N. (1998): Diervillaceae and Linnaeaceae, two new families of caprifolioids. Taxon 47:657-661.

Bell, C. D. and M. J. Donoghue. Phylogeny and biogeography of Morinaceae (Dipsacales) based on nuclear and chloroplast DNA sequences. Organisms, Diversity, and Evolution.

Bell, C. D., Edwards, E. J., Kim, S.-T. & Donoghue, M. J. (2001): Dipsacales phylogeny based on chloroplast DNA sequences. Harvard Pap. in Bot. 6:481-499.

Blackmore, S. & Cannon, M. J. (1983): Palynology and systematics of Morinaceae. Rev. Palaeobot. and Palyn.40:207-226.

Cannon, M. J. & Cannon, J. F. M. (1984): A revision of the Morinaceae (Magnoliophyta-Dipsacales). Bull. Brit. Mus. (Nat. Hist.) Bot. 12:1-35.

Caputo, P. & Cozzolino, S. (1994): A cladistic analysis of Dipsacaceae (Dipsacales). Pl. Syst. Evol. 189:41-61.

Cronquist, A. (1988): The Evolution and Classification of Flowering Plants. New York Botanical Garden, Bronx, New York.

Donoghue, M. J. , Eriksson, T., Reeves, P. A. & Olmstead, R. G. (2001): Phylogeny and phylogenetic taxonomy of Dipsacales, with special reference to Sinadoxa and Tetradoxa (Adoxaceae). Harvard Pap. in Bot.6:459-479.

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Peng, C.-I., Tobe, H. & Takahashi, M. (1995): Reproductive morphology and relationships of Triplostegia (Dipsacales). Bot. Jahrb. Syst. 116:505-516.

Pyck, N., Roels, P. & Smets, E. (1999): Tribal relationships in Caprifoliaceae: evidence from a cladistic analysis using ndhF sequences. Syst. Geogr. Pl. 69:145-159.

Pyck, N. & Smets, E. (2000): A search for the position of the seven-son flower (Heptacodium, Dipsacales): combining molecular and morphological evidence. Pl. Syst. Evol. 225:185-199.

Pyck, N., Van Lysebetten, A., Stessens, J. & Smets, E. (2002): The phylogeny of Patrinieae sensu Grabner (Valerianaceae) revisited: additional evidence from ndhF sequence data. Pl. Syst. Evol. 233:29-46.

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Zhang, W-H., Chen, Z-D., Li, J-H., Chen, H-B. & Tang, Y-C. (2003): Phylogeny of the Dipsacales s.l. based on chloroplast trnL-F and ndhF sequences. Mol. Phylo. Evol. 26:176-189.