Search

Sedum, containing approximately 470 species, is by far the largest genus of Crassulaceae. Three decades of molecular phylogenetic work have provided evidence for the non‐monophyly of Sedum and many more of the 30 genera of Crassulaceae subfam. Sempervivoideae. In this study, we present a broadly sampled and dated molecular phylogeny of Sempervivoideae including 80% of all infrageneric taxa described in Sedum as well as most other genera of the subfamily. We used sequences of one nuclear (ITS) and three plastid markers (matK, rps16, trnL‐trnF). The five major lineages of Sempervivoideae (i.e., Telephium clade, Petrosedum clade, Sempervivum/Jovibarba, Aeonium clade, Leucosedum plus Acre clades) were resolved as successive sister to each other in the phylogenetic analysis of the plastid markers, while in the ITS phylogeny the Petrosedum clade is the closest relative of the Aeonium clade. Our dating analysis of ITS suggests that Sempervivoideae diversified rapidly throughout the Paleocene and Eocene, possibly in the area of the former Tethys and Paratethys archipelago. A biogeographic pattern emerges in which migration out of this ancestral area is linked to pronounced morphological evolution resulting in several distinct lineages recognized as segregate genera thought to be derived from Sedum. These segregate genera, however, have been defined on the basis of strongly homoplasious characters such as degree of petal fusion, petal colouration or flower merism. Moreover, all character states currently used for the delimitation of segregate genera seem to be homoplasious, and each of them can be found in at least one species of Sedum. Extensive literature work led to the conclusion that only few of the monophyletic clades found by us can be defined unambiguously by morphological characters. Mainly for these two reasons, we believe that combination of all 14 genera currently recognized in tribe Sedeae (= clades Leucosedum plus Acre) into Sedum might be the most stable solution of the "Sedum problem". This new Sedum s.l. would then comprise approximately 755 species. [ABSTRACT FROM AUTHOR]

Although not mentioning the hairy character of his material, the description of I Bryophyllum triangulare i provided by Blanco (l.c. 1845) largely coincides with that of material consistently known as I K. tomentosa i . Thirty-seven years earlier, Francisco Manuel Blanco (1778-1845) published the name I Bryophyllum triangulare i Blanco (Fl. Filip., ed. 2: 221. By not adopting " I lanceolata i " in the correct form in I Bryophyllum i when he transferred I C. lanceolata i Blanco non Forssk. to I Bryophyllum i , Blanco was likely following the then widely implemented "Kew Rule" that did not require retention of the epithet of the original species name when a species is transferred to a different genus. However, Merrill (l.c. 1918; l.c. 1923) later agreed with Hamet (l.c. 1907) and rather placed the name I B. triangulare i in the synonymy of I K. laciniata i . [Extracted from the article]

An essential component of biodiversity research and conservation is to accurately delimit species. Traditional morphology‐based taxonomy has faced great challenges in complex taxa. In the last few years, the focus of species delimitations has shifted from defining species using different species concepts to integrating multiple lines of evidence to characterize different aspects of the speciation process. This study employs an integrative taxonomic method to revise the species limits in Rhodiola sect. Trifida, based on multi‐locus sequence data from population‐level sampling, morphometric analyses, and ecological niche modeling. We surveyed 44 populations representing seven previously defined morphological species. We sequenced three plastid markers and three nuclear markers, and employed the coalescent‐based species delimitation method to assess the variational patterns from the molecular data. We also conducted a comprehensive morphological analysis, as well as ecological niche modeling for each species. The multidisciplinary data support Rhodiola liciae and R. sinuata as distinct species, which likely originated by allopatric isolation and ecological speciation. Rhodiola ovatisepala, R. sacra and R. sexifolia are suggested to be synonyms of R. chrysanthemifolia, and the status of R. alterna needs further verification. Our study suggests that the previous taxonomy of this group may depend on too many intra‐lineage variable traits, and showcases the importance of integrative taxonomy for species delimitations in morphologically complex plant groups. [ABSTRACT FROM AUTHOR]

(2908) Proposal to reject the name Crassulaceae subfam. I Cotyledonoideae i , Berger (l.c.) included I Cotyledon i L. (Sp. Pl.: 429. 1995; Van Ham in 't Hart & Eggli, l.c.: 23; Van Ham & 't Hart, l.c.: 126; Mort & al., l.c. 2001, in Amer. J. Bot. 92: 1170. [Extracted from the article]

1931b) did not mention I K. luciae i and, in both papers (Stearn, l.c. 1931a, 1931b), somewhat confusingly rather compared I K. aleurodes i in much more detail to the unrelated Malagasy I K. orgyalis i Baker (in J. Bot. 20: 110. Stearn (l.c. 1931a: 165) mentioned that, among African species, his new species is "most akin" to I Kalanchoe thyrsiflora i and I K. luciae i , distinguishing it from the latter that has "3-lobed squamæ" [nectar scales], while those of I K. aleurodes i are "sub-integrae" [subentire]. I Kalanchoe thyrsiflora i , the first known paddle-leaved species, has bright yellow corolla lobes (Tölken, l.c.: 69 ["deep yellow"]), while, in contrast, the lobe colour of I K. luciae i was later (not in the protologue) recorded as "jaune très lavé" [faded yellow] (Raymond-Hamet & Marnier-Lapostolle in Arch. Mus. [Extracted from the article]

Since the first collection in 1910, botanists have recognized Sarcopilea (Urticaceae) as a dramatic example of con-vergence with succulent woody members of Crassulaceae. Phylogenetic analyses based on nuclear ribosomal DNA ITS and the trnL-F non-coding plastid DNA regions place Sarcopilea in a Neotropical clade of Pilea. A study of the cystolith, pollen and achene morphology, and of hydathode, hydrenchyma, and stornata position was also performed, confirming the molecular results. Across Rosales, leaf succulence is restricted to the genera Pilea and Sarcopilea. Furthermore, all succulent species of Pilea have an abaxial water-storage hydrenchyma layer in their leaves, a condition unique to the genus. The conditions of adaxial stornata (epistomatic, hyperstomatic), as well as hydathodes restricted to the submarginal abaxial leaf surface, were found in all Neotropical leaf-succulent species. Carbon isotope-ratio mass spectroscopy shows Sarcopilea to have C3 photo-synthesis, therefore Crassulacean acid metabolism is still unknown in Rosales. The impact of molecular systematics of Carib-bean endemic genera is discussed. In light of the new phylogenetic placement of Sarcopilea, a replacement name is provided (Pilea fairchildiana). [ABSTRACT FROM AUTHOR]

Broad phylogenetic analyses of Crassulaceae have retrieved a large dade comprising as much as one-third of the species diversity present in the family as a whole. This so-called Acre dade (Sedoideae) includes familiar genera such as Echeveria, Graptopetalum, and Thompsonella, and while it is consistently recovered in studies at the family level, relationships within the clade as well as the monophyly of many of the constituant genera have yet to be established. Results of a phylogenetic study of a genus within the Acre clade, Thompsonella, are here reported. Morphological evidence was gathered and molecular (nuclear ETS and ITS) DNA sequences were generated for forty-seven taxa from the Acre dade, including all recognized members of Thompsonella. Parsimony analysis of the combined data retrieved Thompsonella as a monophyletic group and retrieved species in Graptopetalum, Thompsonella, Echeveria, Pachyphytum and Sedum sect. Pachysedum in a dade; this group was previously identified as the "Echeveria group". Results indicate that only a few genera in the Acre clade are monophyletic and that to establish their generic limits further sampling mainly in the large Echeveria and Sedum genera is needed. Results from morphological and molecular analyses disagree in the position of T. mixtecana. However, an additional restricted analysis performed solely with cpDNA (rps16) placed this species within Thompsonella, suggesting a hybrid origin. [ABSTRACT FROM AUTHOR]

Aeonium (Crassulaceae) comprises species that display a remarkable degree of morphological diversity, including rosette trees, candelabrum shrubs,highly branched shrubs, and woody rosettes. Greenhouse studies have documented that the genus is also diverse in basic photosynthetic metabolism, with C3, CAM, and C3-CAM intermediates present. However, the degree of photosynthetic diversity present in natural populations and between species has never been surveyed. We analyzed stable isotopes of carbon from field-collected species of Aeonium and confirmed that these species are diverse physiologically. Using these data, each species sampled was coded as CAM, C3, or intermediate. This trait was optimized using parsimony onto one arbitrarily selected cladogram for Macaronesian Crassulaceae that had been previously published. These analyses indicated that the ancestral physiological condition for the entire Macaronesian clade of Crassulaceae is C3 photosynthesis. Within Aeonium, one subclade consists largely of species with obligate CAM, one is exclusively intermediate, and two subclades are more variable in photosynthetic metabolism. The ancestral character state for the Aeonium clade is equivocal when the intermediate carbon isotope values were coded as a third character state; however, when these intermediates are considered polymorphic (i.e., facultative CAM), C3 photosynthesis also was ancestral in Aeonium. Concentrated changes tests were conducted to explore associations between CAM and three growth-form attributes, including the candelalbrum shrub and rosette tree growth-forms and monocarpy. These tests revealed no significant association between CAM and monocarpy. The candelabrum shrub growth-form is also not linked with CAM, but CAM has evolved twice within taxa displaying this growth-form. In contrast, the hypothesized correlation between CAM and the rosette tree growth-form was neither rejected nor supported. [ABSTRACT FROM AUTHOR]

Information about the authors' proposal to conserve the plant name Sedum rupestre, from the family of Crassulaceae, with a conserved type is presented. They note that Sedum rupestre has been widely applied to Central European and Mediterranean populations of taxa of Sedum ser. Rupestra A. In order to avoid two disadvantageous plant name changes, the authors propose the conservation of Sedum rupestre, with a Clifford collection as the conserved type.