Research Article |
Corresponding author: Lorenzo Peruzzi ( lorenzo.peruzzi@unipi.it ) Academic editor: Vitor Miranda
© 2018 Francesco Roma-Marzio, Doerte Harpke, Lorenzo Peruzzi.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Roma-Marzio F, Harpke D, Peruzzi L (2018) Rediscovery of Crocus biflorus var. estriatus (Iridaceae) and its taxonomic characterisation. Italian Botanist 6: 23-30. https://doi.org/10.3897/italianbotanist.6.28729
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The Italian endemic Crocus biflorus usually shows white or lilac flowers with three-to-five striking violet longitudinal stripes on the outer tepals, but unstriped plants were recorded in the past. These plants were originally described as C. annulatus subvar. estriatus, and subsequently recombined as a variety of C. biflorus. The rediscovery of such plants in Toscana gave us the opportunity to clarify their systematic relationships, so that we typified the name, and performed karyological and ITS analyses. These plants share the same chromosome number (2n = 2x = 8) and ITS sequence with C. biflorus s. str.
Chromosome number, Herbert, Italian endemics, ITS, typification
The genus Crocus L. (Iridaceae) consists of about 200 recognized species, ranging from western Europe and north-western Africa to western China, with a centre of diversity in the Balkan Peninsula and in Turkey (
This genus is currently subdivided in two sections (C. sect. Crocus and C. sect. Nudiscapus B.Mathew) and 15 series (
Although C. biflorus usually shows white or lilac flowers with three-to-five striking violet longitudinal stripes on the outer tepals (
During a field survey in Empoli (Firenze), we discovered a population of C. biflorus showing all the individuals marked by flowers with unstriped tepals (Fig.
According to Stafleau & Cowan (1979), the Herbert Herbarium is preserved at K, whereas other specimens cited in the protologue (i.e. Herbarium of J.D. Hooker and Herbarium of A.B. Lambert) are preserved at BM, E, G, K, and MANCH (herbarium acronyms follow
Plants were collected in Empoli (Firenze, Toscana) (Fig.
For the karyological study, young developing ovaries were pre-treated with 0.4% colchicine for 3 hours and then fixed in Carnoy fixative solution for 1 hour. Then, after hydrolysis in HCl 1N at 60° C, the material was stained in leuco-basic fuchsine. Meristematic cells were squashed on a slide, adding a drop of acetic orceine, and then analysed under light microscope for the detection of metaphasic plates.
Genomic DNA was extracted from about 10 mg of silica-dried leaf material with the DNeasy Plant DNA Extraction Kit (Qiagen) according to the protocol of the manufacturer. DNA concentration and quality were afterwards checked on 0.8% agarose gels. The ITS region (ITS1, 5.8S rDNA, ITS2) was amplified using the primers ITS-A and ITS-B (
In order to investigate the distribution of Crocus biflorus var. estriatus, we studied specimens from the two main Tuscan herbaria of FI and PI, including the separate collections PI-ARC, PI-CAR, PI-GUAD, PI-PASS, and PI-PELL. Finally, using QGIS 2.18 software, we georeferenced all the specimens and literature data in order to draw a distribution map.
ITALY. Tuscany. Dans les prairies des Cascines, Florence, 26 February 1850, T. Caruel (PI-CAR); Prairie des Cascine pres Florence, Italie, 20 February 1861, T. Caruel (PI); Cascine, Florence, February 1870, A. Archbald (FI); Firenze a Boboli, March 1872, Scafferi (FI); abunde in pratis ambulacri florentini “le Cascine”, 20 February 1874, E. Levier (FI); in prati seccis ambulacrum le Cascine prope Florentiam, 13 February 1876, J. Arcangeli (PI-ARC); Cascine di Firenze nel prato misto con la [?], February 1880, U. Martelli (FI); Environs de Florence (Italie): prairies surtout dans les cascines, March 1888, H. Groves (FI); Firenze nei prati delle Cascine, 19 March 1898, U. Martelli (PI); Cascine prope Florentiam, in pratis, 4 March 1903, G. Stefanini (FI); prope Florentiam (Firenze), vulgatus in pratis loco dicto Le Cascine, 10 March 1904, R. Pampanini et P. Baccarini (FI, PI-GUAD); prope Florentiam alle Cascine, prato al Quercione (ora al Calcio), 9 January 1916, G. Gervasi (FI); Empoli (Firenze), sul Lungarno poco prima di giungere alla Tinaia provenendo da Empoli (WGS84: 43.734473 N, 10.964509 E), incolto con prevalenza di Dactylis glomerata e Artemisia verlotiorum, 27 m s.l.m., 28 January 2018, L. Peruzzi et F. Roma-Marzio (PI n° 011333–011336); Empoli (Firenze), presso la foce dell’Orme (WGS84: 43.726944 N, 10.951719 E), incolto con prevalenza di Dactylis glomerata e Artemisia verlotiorum, 22 m s.l.m., 28 January 2018, L. Peruzzi et F. Roma-Marzio (PI n° 011337). Campania. Valle di San Rocco, 24 April 1834, A. Orsini (FI); ibidem, February 1869, coll. illeg. (PI-CAR); Valle di S. Rocco, 1893, Avellino (FI).
≡Crocus annulatus subvar. estriatus Herb., Botanical Magazine 67: t. 3862. (1841)
≡Crocus annulatus var. estriatus (Herb.) Herb., J. Hort. Soc. London 2: 286 (1847)
≡Crocus biflorus var. estriatus (Herb.) Maw comb. superfl. Gard. Chron. 16: 749 (1881)
(here designated): Crocus pusillus. Edward’s Bot. Reg., 23: plate 1987 [icon] (image available at: https://biodiversitylibrary.org/page/240669). Epitype (here designated): Empoli (Firenze), sul Lungarno poco prima di giungere alla Tinaia provenendo da Empoli (WGS84: 43.734473 N, 10.964509 E), incolto con prevalenza di Dactylis glomerata e Artemisia verlotiorum, 27 m s.l.m., 28 January 2018, L. Peruzzi et F. Roma-Marzio (PI n° 011333; isoepitypes PI n° 011334; PI n° 011335; PI n° 011336. Image of epitype and isoepitypes are available at: http://herbarium.univie.ac.at/database/search.php?collection=PI).
In the protologue,
In all the investigated herbaria we did not find specimens recognisable as original material (Art. 9.3 of ICN,
Our karyological analysis revealed a diploid chromosome count 2n = 2x = 8 (Fig.
Concerning the distribution of unstriped plants, according to herbarium and literature data they are recorded for three different localities in the province of Firenze (Toscana), for a single locality in Campania near Napoli, and for the Botanical Garden of Roma, albeit the only currently confirmed locality is that from Empoli, Firenze (Fig.
Unstriped plants share the same chromosome number (2n = 2x = 8) with C. biflorus s. str. (
Given that C. biflorus is an Italian endemic species (
Considering that many crocuses are known as popular ornamentals (