Ornithogalum L.
In its traditional circumscription Ornithogalum was a rather large Old World genus of ca. 100-150 or even up to 200 species with most representatives in (South) Africa and the Mediterranean region (e.g. Mabberley 2008). However, molecular studies have shown Ornithogalum s.l. to be non-monophyletic (see for instance Manning & al. 2009) and, as a consequence, several smaller monophyletic genera have been reinstated or created subsequently (see Martínez-Azorín & al. 2011 for an overview and a key for the separation of these genera). At present there is no consensus at all as to what generic concept to apply: a modern, analytical one versus a conservative synthetical one. According to Manning & al. (2009) three clades within Ornithogalum s.l. are readily discernable but within these clades many lineages are poorly defined morphologically and thus their recognition at the level of genus is problematical and its practical value severely limited. For reasons of nomenclatural stability and taxonomic utility these lineages could be recognized at infrageneric level. Likewise, Martínez-Azorín & al. (2014) adopted for Flora Iberica a conservative taxonomy and thus a broad generic concept. However, there is no doubt that Ornithogalum s.l. is a paraphyletic assemblage and should be abandoned. Recent western European authors seem to follow a narrower generic concept, e.g. Tison & de Foucault (2014) for France, and this taxonomy is followed here as well.
In this narrow circumscription Ornithogalum counts ca. 20-30 species depending on species delimitation. All are native to the Mediterranean area and adjacent parts of western Asia. One species, however, extends further north and is native in Belgium as well. It is referred to as Ornithogalum umbellatum L. subsp. campestre Rouy by Lambinon & Verloove (2012).
Ornithogalum s.str. remains a taxonomically critical genus in which species delimitation is controversial. Several species, including those of interest in the present account, can only be separated reliably on characteristics of subterranean parts (Tison & de Foucault 2014, Martínez-Azorín & al. 2014). Moreover, a very puzzling nomenclature further adds to the confusion, Ornithogalum umbellatum L. having been typified twice and in very different senses (van Raamsdonk 1982 vs. Stearn 1983). The typification by the latter author now seems to be most widely accepted (e.g. Tison & de Foucault 2014) and is applied here as well. This means that the Belgian native species should be called O. umbellatum L. (syn.: O. angustifolium Boreau, O. vulgare Sailer), while O. divergens Boreau (O. umbellatum as typified by van Raamsdonk 1982) is the correct name for the non-native species. The taxonomy of these two species is also debated. Both are often accepted as mere subspecies of a single variable species (e.g. Stace 2010, Lambinon & Verloove 2012) but they are best given species rank according to recent studies (e.g. Martínez Azorín & al. 2009, Martínez Azorín & al. 2014, Tison & de Foucault 2014).
Numerous species of Ornithogalum are cultivated as ornamentals. Cullen (1986), Jäger & al. (2008) and Graham (2012) provide useful accounts for the genus in cultivation in Europe.
For convenience the three genera now segregated from Ornithogalum s.l. can be distinguished in the following key:
1 Inflorescence racemose, narrow, much longer than wide with 20-300 flowers. Leaves without a white stripe. Capsule triangular in cross section, with blunt margins === Loncomelos
Inflorescence a corymb or a few-flowered raceme (< 20 flowers). Leaves with a white stripe. Capsule with 6 weak or distinct ribs in cross section === 2
2 At least the inner filaments tricuspidate at apex (wings of the filaments with a teeth at either side of the anther). Inflorescence racemose with basal pedicels up to 10 mm long. Flowers campanulate at anthesis, erect to slightly nodding === Honorius
All filaments entire. Inflorescence corymbose to racemose with basal pedicels (much) more than 10 mm long. Flowers stellate at anthesis, erect to erecto-patent === Ornithogalum s.str.
The two species of Ornithogalum s.str. currently found in Belgium are distinguished in the following couplet:
1 Bulb surrounded by numerous (+10), much smaller and leafless bulbils. Lowermost pedicels long and patent (sometimes reflexed), usually at least twice as long as the corresponding bract === Ornithogalum divergens
Bulb surrounded by few (-10) leafy bulbils of variable length and width. Lowermost pedicels erecto-patent and shorter, usually less than twice as long as the corresponding bract (native) === O. umbellatum
Literature:
Cullen J. (1986) Ornithogalum. In: Walters S.M. & al. (eds.), The European Garden Flora, vol. 1: 216-218. Cambridge University Press, Cambridge.
Garbari F., Giordani A., Marcucci R. & Tomadore N. (2003) The genus Ornithogalum L. (Hyacinthaceae) in Italy, XIV: towards a redefinition of infrageneric taxa, with new proposals. Bocconea 16(1): 269-281. [available online at: http://www.herbmedit.org/bocconea/16-0269.pdf]
Garbari F., Peruzzi L. & Tornadore N. (2007) Ornithogalum L. (Hyacinthaceae Batsch) e generi correlati (Subfam . Ornithogaloideae Speta ) in Italia. Atti Soc. tosc. Sci. nat., Mem., Serie B 114: 35-44. [available online at: http://www.stsn.it/serB114/03_garbari_peruzzi_tornadore.pdf]
Graham C. (2012) An overview of Ornithogalum. The Plantsman N.S. 11(1): 16-19.
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.
Lambinon J. (1980) à propos de la publication de « Flora Europaea » volume 5. Remarques chorologiques, taxonomiques et nomenclaturales concernant la flore de la Belgique et des régions voisines. Natura Mosana 34(2): 80-104.
Lambinon J. & Verloove F. (avec coll. Delvosalle L., Toussaint B., Geerinck D., Hoste I., Van Rossum F., Cornier B., Schumacker R., Vanderpoorten A. & Vannerom H.) (2012) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Sixième édition. Jardin botanique national de Belgique, Meise: CXXXIX + 1195 p.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Manning J.C., Forest F., Devey D.S., Fay M.F. & Goldblatt P. (2009) A molecular phylogeny and a revised classification of Ornithogaloideae (Hyacinthaceae) based on an analysis of four plastid DNA regions. Taxon 58(1): 77-107. [available online at: https://www.researchgate.net/publication/233718001_A_molecular_phylogeny_and_a_revised_classification_of_Ornithogaloideae_%28Hyacinthaceae%29_based_on_an_analysis_of_four_plastid_DNA_regions]
Martínez-Azorín M. (2008) Sistemática del género Ornithogalum L. (Hyacinthaceae) en el Mediterráneo occidental: implicaciones taxonómicas, filogenéticas y biogeográficas. Tesis doctoral, Universidad de Alicante [available online at: http://rua.ua.es/dspace/handle/10045/16015]
Martínez-Azorín M., Crespo M.B., Juan A. & Fay M.F. (2011) Molecular phylogenetics of subfamily Ornithogaloideae (Hyacinthaceae) based on nuclear and plastid DNA regions, including a new taxonomic arrangement. Ann. Bot. 107(1): 1-37. [available online at: http://aob.oxfordjournals.org/content/107/1/1.full]
Martínez Azorín M., Crespo M.B. & Juan A. (2014) Ornithogalum. In: Rico E. & al. (eds.), Flora Iberica, vol. 20. Real Jardín Botánico, CSC, Madrid: 188-207. [available online at: http://www.floraiberica.es/floraiberica/texto/pdfs/20_183_25_Ornithogalum.pdf]
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Stearn W.T. (1983) The Linnaean species of Ornithogalum (Liliaceae). Ann. Mus. Goulandris 6: 139-170.
Stolley G. (accessed May 2015) Die Gattung Ornithogalum in Deutschland. [available online at: http://offene-naturfuehrer.de/web/Die_Gattung_Ornithogalum_in_Deutschland_(Gregor_Stolley)]
Tison J.-M. & de Foucault B. (coord.) 2014) Flora Gallica. Flore de France. Editions Biotope, Mèze : xx + 1196 p.
Tornadore N. & Garbari F. (1979) Il genere Ornithogalum L. (Liliaceae) in Italia. 3. Contributo alla revisione citotassonomica. Webbia 33(2): 379-423.
Van Raamsdonk L.W.D. (1982) Biosystematic studies on the umbellatum-angustifolium complex in the genus Ornithogalum L. I. Typification and taxonomy. Proc. Kon. Ned. Akad. Wetensch. C 85: 563-574.
Zahariadi C. (1980) Ornithogalum. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 5. Cambridge University Press, Cambridge: 35-40.