Carduncellus-Carthamus Complex (Asteraceae) Based on ITS Sequences
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Plant Syst. Evol. 221:89-105 (2000) Plant Systematics and Evolution © Springer-Verlag 2000 Printed in Austria Generic delimitation and phylogeny of the Carduncellus-Carthamus complex (Asteraceae) based on ITS sequences R. Vilatersana, A. Susanna, N. Garcia-Jacas, and T. Garnatje Institut Botfinic de Barcelona (CSIC), Barcelona, Spain Received August 18, 1999 Accepted October 21, 1999 Abstract. Within the Mediterranean complex 50 species (Dittrich 1977). These two genera Carduncellus-Carthamus, taxonomic classification share a native distribution ranging from the has proven problematic. Numerous attempts to Iberian Peninsula and Morocco to West Asia, clarify the relative systematic boundaries have but the core of Carduncellus centers in the included splitting Carduncellus and Cartharnus western Mediterranean (Iberian Peninsula and into several genera, but none of these proposed North Africa, eastward to Greece and Egypt), classifications have been generally accepted. For a comprehensive resolution of the relationships while Carthamus centers in the eastern Medi- within this group, we used sequences of the terranean Basin, except for a small section Internal Transcribed Spacers (ITS) of nuclear endemic to southern Spain and Morocco ribosomal DNA. The results indicate that the (Fig. 1). complex should be classified into four genera: In addition, some species such as Car- Carduncellus, Carthamus, Ferneniasia and Phonus. tharnus lanatus L., probably of hybrid origin, The relationship between the western group and Carthamus leucocaulos Sibth. & Sm. are (Carduncellus, Femeniasia and Phonus) and the widely naturalized as noxious weeds in the eastern genus Carthamus are not resolved by western Mediterranean region, as well as in analysis of ITS sequences, but the two groups Mediterranean climatic regions of Argentina, are probably not close relatives. The ITS classifi- Australia, California, and South Africa (Ashri cations corresponded with biogeography and less and Knowles 1960, Hanelt 1963, Estilai and with morphological characters, which have also been the main source of confusion in traditional Knowles 1978). The wild origin is unknown for classifications. Most of the unusual morphological the cultivated species Carthamus tinctorius L. features in the Carduncellus-Carthamus complex (safflower), although it is widely grown as an appear to be reversals to ancestral character important source of oil in subtropical coun- states. tries (Hanelt 1963, 1976) and as a substitute for saffron. Key words: Carduncellus, Carthamus, Femeniasia, The subtribe position of this complex Phonus, phylogeny, ITS sequences. within Cardueae is problematic and many genera are not yet clearly delineated. The In the Mediterranean basin, the complex of existing confusion was compounded by the two Asteraceae-Cardueae genera, Carduncellus recent incorporation of a new genus, Femeni- Adanson and Carthamus L., comprises about asia Susanna (Susanna et al. 1995, Susanna 90 R. Vilatersana et al.: Phylogeny of Carduncellus-Carthamus Fig. 1. Geographic distribution of the genera of the complex. Light grey: Carduncellus. Dark grey: Carthamus (excluded the cosmopolitan section Atractylis). Diamonds: Phonus (=Carthamus sect. Thamnacanthus). Inverted triangle: Femeniasia and Vilatersana 1996, Wagenitz and Hellwig Carduinae, but highly unusual in Centaurei- 1996), into the complex. nae. Secondly, the caducous single pappus Subtribal placement. Cassini (1819) includ- found in some species of Carduncellus (Cassini ed Carduncellus and part of Carthamus in the 1819, Dittrich 1969) and Femeniasia (Susanna subtribe Carduinae, while classifying Car- 1988) is more representative of the subtribe thamus sensu stricto in the Centaureinae. Later Carduinae than the tribe Centaureinae. How- classifications proposed a new subtribe Carth- ever, the spiny habit could be easily attributed aminae for Carduncellus and Carthamus, posi- to secondary adaptation against predators; and tioned between the two major subtribes of the the reduction from a double to a single pappus Cardueae: Carduinae and Centaureinae (De occurs frequently in the subtribe Centaureinae, Candolle 1838, Nyman 1878-1890). Subse- thus it provides minimal systematic value quently, Godron (1852) and Battandier (Dittrich 1968, 1969; Wagenitz and Hellwig (1890) reverted to the classification of Cassini 1996). For this reason, current general opinion (1819) and moved Carduncellus to Carduinae favors classifying the entire complex in Cen- and Carthamus to Centaureinae. After that, taureinae (Dittrich 1977, Bremer 1994, Susan- Bentham (1873) classified both genera in the na et al. 1995, Wagenitz and Hellwig 1996). subtribe Centaureinae, with concurrence by Generic delineation. At the generic level, Hoffmann (1894). Similarly, Femeniasia was the main problem in the complex is the described and classified in Carduinae (Susanna delineation of Carduncellus and Carthamus. 1988), and was later transferred to Centaur- Unfortunately, numerous attempts to solve einae (Bremer 1994, Susanna et al. 1995, this central problem by splitting both genera Susanna and Vilatersana 1996, Wagenitz and have created even greater quandary. For Hellwig 1996). example, the systematic position is not clear Two peculiar morphological traits are pri- for two genera split from Carthamus (Kent- marily responsible for this fluctuating subtribal rophyllum Necker and Phonus Hill) and placement. First, most species in the complex another genus (Larnottea Pomel) segregated have spiny leaves, a frequent characteristic in from Carduncellus. Also problematic are two R. Vilatersana et al.: Phylogeny of Carduncellus-Carthamus 91 Table 1. Different generic classifications of the complex Cassini (1819) De Candolle (1838) Pomel (1874) Kentrophyllum Kentrophyllum Kentrophyllum sect. Atraxyle Onobroma sect. Odontognathia sect. Euonobroma sect. Thamnacantha sect. Cirsiastrum Car duncellus Carduncellus Carduncellus Onobroma Carthamus Carthamus Durandoa Bentham (1873) Battandier (1890) Hanelt (1963) Boissier (1875) Hoffmann (1894) Kentrophyllum Carthamus sect. Durandoa sect. Atractylis Carduncellus sect. Atraxyle sect. Carthamus sect. Lepidopappus Carthamus Carthamus sect. Odontognathius sect. Thamnacanthus Car duncellus sect. Cyanoidei Carduncellus sect. Cirsiastri sect. Phalolepides sect. Carduncellus L6pez Gonzfilez (1990) Carthamus sect. Atractylis sect. Carthamus sect. Odontognathius Phonus Lamottea CarduncelIus rare North African endemics, Carduncellus Carduncellus and Carthamus. The line mareoticus (Del.) Hanelt and Carduncellus separating Carduncellus from Carthamus has fruticosus (Maire) Hanelt, which have been fluctuated widely depending on the characters classified in four different genera: Carduncellus, chosen. L6pez Gonzfilez (1990) lists three Carthamus, Femeniasia and Phonus. These and potential criteria for differentiating between other conflicting generic classifications are Carthamus and Carduncellus: structures of the reviewed in Table 1. Finally, there is the pappus and the pericarp and morphology of question of where the monotypic genus Fe- the middle bracts of the capitulum. meniasia belongs in the complex. By the time it Two main types of pappus are found in the was first described on the basis of a single rare Carduncellus-Carthamus complex. The more endemic species (Susanna 1988), the relation- common type is a double pappus, composed of ship of this genus to the Carduncellus-Car- two whorls, a very short convergent inner thamus group was unsuspected and it was first pappus and an outer pluriseriate pappus with classified within the Carduinae. longer, unequal, linear or paleaceous setae To minimize confusion, this paper follows (Dittrich 1968, 1969). This type of pappus can the nomenclature of Hanelt (1963). be persistent or deciduous and is frequently 92 R. Vilatersana et al.: Phylogeny of Carduncellus-Carthamus absent in the peripheral cypselas. This pappus (1874). He described it as Durandoa Pomel, type is present in Carthamus and in a group of but this illegitimate name has been corrected to Carduncellus species that has been segregated Phonus (cf. Ldpez Gonz/tlez 1990). Species of to a different genus (Lamottea) on the basis of this section of Cartharnus possess some con- this character. The second type of pappus is flicting characters that deviate from the rest of characterized by simple, more or less equal the genus. They are subshrubs, whereas the linear setae, deciduous as a single unit by rest of the species of Carthamus are annual. means of a basal ring. This pappus is typical of The cypselas resemble those of Carduncellus Carduncellus sensu stricto (excluding Lamo- by having a semideciduous pappus, and the ttea). Pappus characteristics are the basis of pericarp is undifferentiated (Dittrich 1969). classifications proposed by De Candolle (1838), Their geographic distribution is western Medi- Boissier (1873), Bentham (1873), Battandier terranean with two narrow endemics centered (1890), and Ldpez Gonzfilez (1990) (Table 1). in southern Spain and Morocco (Fig. 1). It was primarily on the basis of pericarp However, species of Phonus lack the append- structure that some species were segregated ages of the middle bracts typical of Card- from the complex into a new genus. Members uncellus, a fact that led Hanelt (1963, 1976) to of this genus (Phonus) are characterized by an retain them in Carthamus, while recognizing undifferentiated pericarp (Dittrich 1969). that this classification was a conservative Ldpez Gonzfilez (1990) concurred that this