Camassia Lindl.
Camassia is a genus of six North American species (Ranker & Hogan 2002). It forms a monophyletic clade within Agavaceae (Smith & al. 2008). Species delimitation is often difficult due to high morphological variability. Especially in areas where taxa occur sympatrically hybridization events may further contribute to the complexity. However, despite evidence that Camassia species hybridize, sampling sympatric populations revealed only a single case of introgression of plastid haplotypes (Fishbein & al. 2010).
All species are highly appreciated ornamentals, also in Europe (e.g. King 1986, Jäger & al. 2008). One species, Camassia leichtlinii (Baker) S. Watson, has been recorded as an alien in Belgium.
Literature:
Archibald J.K., Kephart S.R., Theiss K.E., Petrosky A.L. & Culley T.M. (2015) Multilocus phylogenetic inference in subfamily Chlorogaloideae and related genera of Agavaceae – Informing questions in taxonomy at multiple ranks. Molecular Phylogenetics and Evolution 84: 266-283. [available online at: https://www.researchgate.net/profile/Theresa_Culley/publication/270913188_Multilocus_phylogenetic_inference_in_subfamily_Chlorogaloideae_and_related_genera_of_Agavaceae__Informing_questions_in_taxonomy_at_multiple_ranks/links/54f119630cf24eb87941969d.pdf]
Culley T.M., Leng J.F., Kephart S.R., Cartieri F.J. & Theiss K.E. (2013) Development of 16 microsatellite markers within the Camassia (Agavaceae) species complex and amplification in related taxa. Appl. Plant Sci. 1(8) [available online at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103445/].
Fernandez A. & Davina J.R. (1991) Heterochromatin and genome size in Fortunatia and Camassia (Hyacinthaceae). Kew Bull. 46(2): 307-316.
Fishbein M., Kephart S.R., Wilder M., Halpin K.M. & Datwyler S.L. (2010) Phylogeny of Camassia (Agavaceae) Inferred from Plastid rpl16 Intron and trnD–trnY–trnE–trnT Intergenic Spacer DNA Sequences: Implications for Species Delimitation. Syst. Bot. 35(1): 77-85.
Gould F.W. (1942) A systematic treatment of the genus Camassia Lindl. Amer. Midl. Naturalist 28: 712-742.
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
King C.J. (1986) Camassia. In: Walters S.M. & al. (eds.), The European Garden Flora, vol. 1. Cambridge University Press, Cambridge: 215-216.
Ranker T.A. & Hogan T. (2002) Camassia. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 26. Oxford University Press, New York-Oxford: 303-307. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=105373]
Smith C.I., Pellmyr O., Althoff D.M., Balcázar-Lara M., Leebens-Mack J. & Segraves K.A. (2008) Pattern and timing of diversification in Yucca (Agavaceae): specialized pollination does not escalate rates of diversification. Proc. Biol. Sc. 275: 249-258. [available online at: http://rspb.royalsocietypublishing.org/content/275/1632/249]
Speta F. (1987) Die verwandtschaftlichen Beziehungen von Brimeura Salisb.: ein Vergleich mit den Gattungen Oncostema Rafin., Hyacinthoides Medic. und Camassia Lindl. (Hyacinthaceae). Phyton (Austria) 26(2): 247-310.
Uyeda J.C. & Kephart S.R. (2006) Detecting Species Boundaries and Hybridization in Camassia quamash and C. leichtlinii (Agavaceae) Using Allozymes. Systematic Botany 31(4): 642-655.