Cichorieae Portal

Circumscription of the Cichorieae

The traditional circumscription of the Cichorieae as a conveniently recognized tribe, diagnosed by the unique combination of homogamous capitula with 5-dentate, ligulate flowers and the presence of milky latex, has been altered recently on the basis of molecular phylogenetic analyses by Gemeinholzer & al. (in Kilian & al. 2009) to accommodate the two genera, Gundelia and Warionia, of hitherto uncertain relationships, associated with the Arctotideae (Gundelia) and the Mutisieae (Warionia), respectively. Both have milky latex but otherwise homogamous capitula with tubular flowers. Hence, by inclusion of these genera the homogamous capitula with 5-dentate, ligulate flowers no longer characterize all the members of the tribe.

Neither milky latex nor capitula with only 5-dentate, ligulate flowers have been autapomorphies of the Cichorieae. Milky latex is otherwise present in some genera of Arctotideae, Cardueae, Liabeae, Mutisieae and Vernonieae (Carlquist 1976), and in a few cases in the Asteroideae (Augier & Mérac 1951; Wagenitz 1976; Bremer 1987, 1994). Milky latex, however, is associated with different anatomical structures in the Compositae. Lactiferous canals, as they are characteristic for all Cichorieae, are otherwise only present in the aerial plant parts of the Arctotideae, whereas other tribes of the Cichorioideae merely have lactiferous cells (Augier & Mérat 1951; Wagenitz 1976). Homogamous capitula with 5-dentate, ligulate flowers are present in a few genera of Mutisieae (Catamixis, Glossarion, Hyaloseris; Bremer 1987, 1994) and, quite evidently by convergent evolution, in the Heliantheae-Coreopsidinae (Fitchia) of subfamily Asteroideae (Carlquist 1957); 5-dentate, ligulate marginal flowers occur in the Vernonieae (Stokesia; Bremer 1987, 1994).

The presence of lactiferous canals in both the subterranean and aerial plant parts seem to be an exclusive feature of the Cichorieae in the present circumscription including Gundelia and Warionia (Augier & Mérac 1951; Wagenitz 1976; Bremer 1987, 1994). Moreover, Gundelia and Warionia share the presence of both (functional) oil ducts and latex canals in the roots (Augier & Mérac 1951) with Scolymus and Scorzonera s.l. (Tieghem 1872; Hoffmann 1890-94; Col 1903-04), while non-functional (relict) oil ducts have been reported from Tragopogon (Tieghem 1885) and Krigia (Holm 1926).

Gundelia, with a much-derived synflorescence of one-flowered capitula aggregated to secondary capitula (Classen-Bockhoff & al. 1989), has spiny leaves and pollen similar to Scolymus (Blackmore 1981; Robinson 1994). Gundelia in fact has been shown to form a monophyletic trichotomy with Scolymus and the rest of the Cichorieae by Karis & al. (2001; based on ndhF data). Based on a much broader sampling especially for the basally branching portions of the Cichorieae, Gemeinholzer & al. (in Kilian & al. 2009) have shown that Gundelia forms a clade with Catananche, Hymenonema and Scolymus, which is treated as the subtribe Scolyminae.

The monospecific Warionia has been shown by Funk & al. (2004; based on trnL-F, ndhF and ITS data) to form a sister-group relationship to the Cichorieae, and by Goertzen & al. (2003: fig. 3; based on ITS data) to form the basalmost branch of the Cichorieae clade. Based on these results, Jeffrey (2006) re-established a separate tribe Gundelieae next to Cichorieae to include both Gundelia and Warionia. Warionia, with densely pilose achenes (rare in the Cichorieae but also occurring, e.g., in many species of Scorzonera), is branching off basally and found to be the sister-group to all other Cichorieae also in the analyses by Gemeinholzer & al. (in Kilian & al. 2009). Having emphasised its closer relationship to the Cichorieae than to any other tribe, these results led Gemeinholzer & Kilian (in Kilian & al. 2009) to establish for Warionia a new subtribe of its own, Warioniinae, in the Cichorieae.

Major clades and recognition of subtribes within the Cichorieae

Whitton & al. (1995) using chloroplast DNA restriction site variation upon 60 Cichorieae taxa were the first to address relationships among major lineages of the tribe and their results agree very well with two more recent attempts by Gemeinholzer & al. (in Kilian & al. 2009), using DNA sequences of the nuclear ITS region and covering 438 taxa, and Tremetsberger & al. (2012), using a subset of 49 species from the former analysis and focusing on divergence time estimations. All analyses revealed similar major lineages.
The analysis by Gemeinholzer & al. (in Kilian & al. 2009) and Tremetsberger & al. (2012) both revealed five major clades, with a total of eleven subclades, within the tribe.

The first three main clades branching off basally comprise c. 20 % of the species of the tribe (for species proportions here and in the following Hieracium, Pilosella and Taraxacum not considered):

• Clade 1 includes solely Warionia (recognized as the subtribe Warioniinae).
• Clade 2 represents the subtribe Scorzonerinae.
• Clade 3 represents the subtribe Scolyminae

The two main clades 4 and 5 comprise roughly 80 % of the species of the tribe:

• Clade 4 includes five subclades, representing the subtribes Chondrillinae, Crepidinae, Hyoseridinae, Hypochaeridinae and Lactucinae. This main clade comprises 2/3 of the species of the tribe.
• Clade 5 includes three subclades, representing the subtribes Cichoriinae, Hieraciinae and Microseridinae s.l. This main clade comprises somewhat more than 10 % of the species of the tribe.

The backbone of the tree is essentially unresoved and reconstructed differently by Kilian & al. (2009) and Tremetsberger & al. (2012). In the analysis by Kilian & al. (2009) the main clades 4 and 5 group with clade 3 (Scolyminae), whereas the main clades 4 and 5 group with clade 2 (Scorzonerinae) in that by Tremetsberger & al. (2012). The latter topology with the Scolyminae being sister to clade 2 (Scorzonerinae) + clades 4 and 5 is also corroborated by the analyses of chloroplast restriction sites by Whitton & al.(1994) and of chloroplast ndhF sequences by Karis & al. (2001).

Age of the Cichorieae

The estimated minimum age for the most recent common ancestor of the Cichorieae was revealed as c. 26 (23.2-30.3) mya, indicating that the tribe originated no later than Oligocene, and from the inferred N African-Mediterranean ancestral area of Cichorieae (including Gundelieae, Funk & al. 2005), N Africa seems the most plausible region of origin (Tremetsberger & al. 2012). The clades 4 and 5 diversified no later than Middle/Late Miocene or Early Pliocene (c. 21 (16.8-24.4) mya) (Tremetsberger & al. 2012).

References

Augier J. & Mérac M.-L. du 1951: La phylogénie des Composées. – Revue des Sciences 89: 167-182.

Blackmore S. 1981: Palynology and intergeneric relationships in subtribe Hyoseridinae (Compositae: Lactuceae). – Bot. J. Linn. Soc. 82: 1-13.

Bremer K. 1987. Tribal interrelationships of the Asteraceae. – Cladistics 3: 210-253.

Bremer K. 1994: Asteraceae. Cladistics and classification. – Portland: Timber.

Carlquist S. 1976: Tribal interrelationships and phylogeny of the Asteraceae. – Aliso 8: 465-492.

Classen-Bockhoff R., Froebe H. A. & Langerbeins D. 1989: Die Infloreszenzstruktur von Gundelia tournefortii L. (Asteraceae). – Flora 182: 463-479.

Col A. 1903-04: Recherches sur l’appareil sécréteur des Composées. – J. Bot. (Morot) 17: 252-318, 18: 110-133, 153-175.

Funk V. A., Chan R. & Keeley S. C. 2004: Insights into the evolution of the tribe Arctoteae (Compositae: subfamily Cichorioideae s.s.) using trnL-F, ndhF and ITS. – Taxon 53: 637-655.

Funk V. A., Bayer R. J., Keeley S., Chan R., Watson L., Gemeinholzer B., Schilling E., Panero J. L., Baldwin B. G., Garcia-Jaca N., Susanna A. & Jansen R. K. 2005: Everywhere but Antarctica: using a supertree to understand the diversity and distribution of the Compositae. – Biologiske Skrifter 55: 343–374.

Goertzen L. R., Cannone J. J., Gutell R. R. & Jansen R. K. 2003: ITS secondary structure derived from comparative analysis: implications for sequence alignment and phylogeny of the Asteraceae. – Molec. Phylogenet. Evol. 29: 216-234.

Hoffmann O. 1890–1894: Compositae. – Pp. 87–387 in: Engler A. & Prantl K. (ed.), Die natürlichen Pflanzenfamilien 4(5). – Leipzig: Engelmann.

Holm T. 1926: Studies in the Compositae. I. Krigia virginica (L.) Willd. – Amer. Midland Naturalist 10: 1-17.

Jeffrey C. 2006: Tribe Gundelieae DC. ex Lecoq & Juillet (1831). – Pp. 199-200 in: Kadereit J. W. & Jeffrey C. (ed.), The families and genera of vascular plants 8. – Berlin: Springer.

Karis P. O., Eldenäs P. & Källersjö M. 2001: New evidence for the systematic position of Gundelia L. with notes on delimitation of Arctoteae (Asteraceae). – Taxon 50: 105-114.

Kilian N., Gemeinholzer B. & Lack H. W. 2009: Tribe Cichorieae. – In: Funk V. A., Susanna A., Stuessy T. & Bayer R. (ed.), Systematics, evolution, and biogeography of the Compositae. – Vienna: IAPT.

Robinson H. 1994: Notes on the tribes Eremothamneae, Gundelieae and Moquinieae, with comparisons of their pollen. – Taxon 43: 33-44.

Tieghem P. van 1872: Mémoire sur les canaux sécreteurs des plantes. – Ann. Sci. Nat., Bot., ser. 5, 16: 96-201.

Tieghem P. van 1885: Second mémoire sur les canaux sécreteurs des plantes. – Ann. Sci. Nat., Bot., ser. 7, 1: 5-96.

Tremetsberger K., Gemeinholzer B., Zetzsche H., Blackmore S., Kilian N. & Talavera S. 2012: Divergence time estimation in Cichorieae (Asteraceae) using a fossil-calibrated relaxed molecular clock. – Org. Divers. Evol. 13: 1-13. // ➪ //

Wagenitz G. 1976: Systematics and phylogeny of the Compositae (Asteraceae). – Pl. Syst. Evol. 125: 29-46.

Whitton J., Wallace R. S. & Jansen R. K. 1995: Phylogenetic relationships and patterns of character change in the tribe Lactuceae (Asteraceae) based on chloroplast DNA restriction site variation. – Canad. J. Bot. 73: 1058-1073.