Glebionis Cass.
(syn.: Xanthophthalmum Schultz-Bip.)
Glebionis, a segregate of Chrysanthemum L., is a small genus of two species, originally native to the Mediterranean region and western Asia. Both species are weeds of arable land and have spread far beyond their native range. They are sometimes cultivated as ornamentals as well. Glebionis segetum (L.) Fourr. (syn.: Chrysanthemum segetum L., Xanthophthalmum segetum (L.) Schultz-Bip.) is usually claimed as native in Belgium but it is in fact, at most, an archaeophyte.
Glebionis segetum is increasingly sown in wild flower seed mixtures. Some races are very aberrant: leaves deeply pinnatisect, heads up to 50 mm across, plants up to 100 cm tall, etc. In general appearance they perfectly match with Glebionis coronaria (var. coronaria, with entirely yellow ligules) but all achenes are unwinged and eglandular (Lambinon & al. 2006).
1 Achenes with sessile glands, those of the ligular florets winged. Ligules white with a yellow base or yellow. Upper leaves 2- to 3-pinnatisect === Glebionis coronaria
Achenes eglandular, those of the ligular florets not winged. Ligules yellow. Upper leaves usually nearly entire to coarsely dentate (rarely pinnatisect in cultivars) (native) === G. segetum
Literature:
Bremer K. & Humphries C.J. (1993) Generic monograph of the Asteraceae-Anthemideae. Bull. Nat. Hist. Mus., London 23(2): 1-177.
Cullen J. (2000) Xanthophthalmum. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 615.
Guillot Ortiz D. (2010) La tribu Anthemideae Cass. (Asteraceae) en la flora alóctona de la Península Ibérica e Islas Baleares. Monografías de la Revista Bouteloua 9: 158 pp. [available online at: http://www.floramontiberica.org/Bouteloua/Monografia_Bouteloua_09.htm]
Heywood V.H. (1976) Chrysanthemum. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 4. Cambridge University Press, Cambridge: 168-169.
Lambinon J., Clesse B. & Verloove F. (2006) Biodiversité et naturalité de la flore: un nouvel exemple en Wallonie de l’ambiguïté de ces critères, celui du Chrysanthème des moissons, Glebionis segetum. L’Erable 30(2): 1-2.
Oberprieler C., Himmelreich S. & Vogt R. (2007) A new subtribal classification of the tribe Anthemideae (Compositae). Willdenowia 37: 89-114. [available online at: http://www.bgbm.org/sites/alienplantsbelgium.bedefault/files/documents/wi37-1Oberprieler%2Bal.pdf]
Sell P. & Murrell G. (2006) Flora of Great Britain and Ireland. Vol. 4 Campanulaceae – Asteraceae. Cambridge University Press, Cambridge: XXVIII + 624 p.
Strother J.L. (2006) Glebionis. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 19. Oxford University Press, New York-Oxford: 554-555. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=113620]