References
- AlvarezI, WendelJF. 2003. Ribosomal ITS sequences and plant phylogenetic inference. Mol Phylogenet Evol29: 417–434.
- ArnoldML. 2006. Evolution through genetic exchange. Oxford: Oxford University Press.
- ArrigoniPV. 2007. Contributo alla conoscenza della flora della Sardegna: Nuove specie di Taraxacum e altri reperti. Parlatorea9: 87–94.
- BanchevaS, GeraciA, RaimondoFM. 2011. Assessing the genetic diversity of Centaurea parlatoris group (sect. Dissectae, Compositae) in Sicily using isozymes. Plant Biosyst145: 778–785.
- Barlow-IrickPL. 2002. Biosystematic analysis of the Cirsium arizonicum complex of the southwestern United States. PhD thesis, University of New Mexico.
- BediniG, GarbariF, PeruzziL. 2012. Karyological knowledge of the Italian vascular flora as inferred by the analysis of “Chrobase.it”. Plant Biosyst146(4): 889–899.
- BurešP, ŠmardaP, RotreklováO, OberreiterM, BurešováM, KoneČnýJ, et al. 2010. Pollen viability and natural hybridization of Central European species of Cirsium. Preslia82: 391–422.
- BurgarellaC, LorenzoZ, Jabbour-ZahabR, LumaretR, GuichouxE, PetitRJ, et al. 2009. Detection of hybrids in nature: Application to oaks (Quercus suber and Q. ilex). Heredity102: 442–452.
- ClementM, PosadaD, CrandallKA. 2000. TCS: A computer program to estimate gene genealogies. Mol Ecol9: 1657–1659.
- CorriveauJL, ColemanAW. 1988. Rapid screening method to detect potential biparental inheritance of plastid DNA and results for over 200 angiosperm species. Am J Bot75: 1443–1458.
- Di MartinoA, TrapaniS. 1967. Flora e vegetazione delle Isole di Favignana e Levanzo nell'Arcipelago delle Egadi. I. Favignana. Lav Ist Bot Giard Colon Palermo22: 122–228.
- DownieSR, Katz-DownieDS. 1996. A molecular phylogeny of Apiaceae subfamily Apioideae: Evidence from nuclear ribosomal DNA internal transcribed spacer sequences. Am J Bot83: 234–251.
- DoyleJJ, DoyleJL. 1987. A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochem Bull19: 11–15.
- DoyleJJ, DoyleJL, RauscherJT, BrownAHD. 2004. Evolution of the perennial soybean polyploid complex (Glycine subgenus Glycine): A study of contrasts. Biol J Linn Soc82: 583–597.
- EllstrandNC, ElamDR. 1993. Population genetic consequences of small population size: Implications for plant conservation. Ann Rev Ecol Syst24: 217–242.
- FennaneM, Ibn TattouM. 1998. Catalogue des plantes vasculaires rares, menacées ou endémiques du Maroc. Bocconea8: 5–243.
- GenovartM. 2009. Natural hybridization and conservation. Biodivers Conserv18: 1435–1439.
- GussoneG. 1844. Florae siculae synopsis. vol. 2. Napoli: Ex Typis Tramater.
- HeynCC, JoelA. 1983. Reproductive relationships between annual species of Calendula (Compositae). Plant Syst Evol143: 311–339.
- HughesJF, BrownGK. 2004. A putative hybrid swarm within Oönopsis foliosa (Asteraceae: Astereae). West N Am Nat64: 109–124.
- LanzaD. 1919. Monografia del genere Calendula L. Palermo: Scuola Tip. “Boccone del Povero”.
- LevinDA. 2002. Hybridization and extinction: In protecting rare species, conservationists should consider the dangers of interbreeding, which compound the more well-known threats to wildlife. Am Sci90: 254–261.
- López-PujolJ, Garcia-JacasN, SusannaA, VilatersanaR. 2012. Should we conserve pure species or hybrid species? Delimiting hybridization and introgression in the Iberian endemic Centaurea podospermifolia. Biol Conserv152: 271–279.
- MalletJ. 2007. Hybrid speciation. Nature446: 279–283.
- MeikleRD. 1976. Calendula L. In: TutinTG, HeywoodVH, BurgesNA, MooreDM, ValentineDH, WaltersSM, editors. Flora Europaea, 4. Cambridge: Cambridge University Press. pp. 206–207.
- MontmollinB de, StrahmW, editors. 2005. The top 50 Mediterranean Island plants: Wild plants at the brink of extinction, and what is needed to save them. IUCN SSC Mediterranean Islands Plant Specialist Group. IUCN: Gland and Cambridge.
- NoraS, CastroS, LoureiroJ, GonçalvesAC, OliveiraH, CastroM, et al. 2013. Flow cytometric and karyological analyses of Calendula species from Iberian Peninsula. Plant Syst Evol, 10.1007/s00606-013-0767-0.
- OhleH. 1974. Beiträge zur Taxonomie der Gattung Calendula. II. Taxonomische Revision der südeuropaischen perennierenden Calendula-Sippen. Feddes Repert85: 245–283.
- PeruzziL, BediniG, AndreucciA. 2012. Homoploid hybrid speciation in Doronicum L. (Asteraceae)? Morphological, karyological and molecular evidences. Plant Biosyst146(4): 867–877.
- PignattiS. 1982. Flora d'Italia. vol. 3. Bologna: Edagricole.
- RaimondoFM, ScialabbaA, ZeccaG, GrassiF, CasazzaG, MinutoL. 2012. Genetic diversity in the endangered Sicilian endemic Brassica rupestris: Proposals for a conservation strategy. Plant Biosyst146(4): 847–856.
- RiesebergLH. 2006. Hybrid speciation in wild sunflowers. Ann Missouri Bot Gard93: 34–48.
- RotreklováO. 2008. Hieracium subgen. Pilosella: Pollen stainability in sexual, apomictic and sterile plants. Biologia63: 63–66.
- ShawJ, LickeyEB, SchillingEE, SmallRL. 2007. Comparison of whole chloroplast genome sequences to choose noncoding regions for phylogenetic studies in angiosperms: The tortoise and the hare III. Am J Bot94: 275–288.
- SimmonsMP, OchoterenaH. 2000. Gaps as characters in sequence-based phylogenetic analyses. Syst Biol49: 369–381.
- SoltisDE, MavrodievEV, DoyleJJ, RauscherJT, SoltisPS. 2008. ITS and ETS sequence data and phylogeny reconstruction in allopolyploids and hybrids. Syst Bot33: 7–20.
- SoltisDE, SoltisPS, PiresJC, KovarikA, TateJA, MavrodievE. 2004. Recent and recurrent polyploidy in Tragopogon (Asteraceae): Cytogenetic, genomic and genetic comparisons. Biol J Linn Soc82: 485–501.
- TroiaA. 2011. Strategie di gestione delle popolazioni di Calendula maritima Guss. (Asteraceae). Naturalista Sicil35: 51–63.
- TroiaA, GreuterW, RaimondoFM. 2012. Revised lectotypification of the name Calendula maritima (Asteraceae). Phytotaxa71: 48–51.
- TroiaA, PastaS. 2006. Calendula maritima. In: IUCN red list of threatened species. Version 2012.1. Available: http://www.iucnredlist.org. Accessed Jul 2012 20.
- TroiaA, RaimondoFM, editors. 2011. Proceedings of the international meeting “the Calendula of Trapani, an emblematic threatened Mediterranean endemic,” 20 February 2010, Trapani. Naturalista Sicil 35: 1–129. Available: http://www.sssn.it/indice4.htm. Accessed Aug 2012 3.
- WhiteTJ, BrunsT, LeeS, TaylorJW. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: InnisMA, GelfandDH, SninskyJJ, WhiteTJ, editors. PCR protocols: A guide to methods and applications. New York: White Academic Press, Inc. pp. 315–322.
- WolfD, TakebayashiN, RiesebergL. 2001. Predicting the risk of extinction through hybridization. Conserv Biol15: 1039–1053.
- WorleyAC, SawichL, GhazviniH, FordBA. 2009. Hybridization and introgression between a rare and a common lady's slipper orchid, Cypripedium candidum and C. parviflorum (Orchidaceae). Botany87: 1054–1065.