Research Article |
Corresponding author: Anna Scoppola ( scoppola@unitus.it ) Academic editor: Lorenzo Peruzzi
© 2016 Anna Scoppola, Edda Lattanzi, Liliana Bernardo.
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:
Scoppola A, Lattanzi E, Bernardo L (2016) Distribution and taxonomy of the Italian clovers belonging to Trifolium sect. Vesicastrum subsect. Mystillus (Fabaceae). Italian Botanist 2: 7-27. https://doi.org/10.3897/italianbotanist.2.10361
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In this paper, we focused our attention on the taxonomy and distribution in Italy of taxa belonging to Trifolium sect. Vesicastrum subsect. Mystillus. A short description of these closely related clovers, based on the study of fresh plant material, revision of herbarium specimens, and analysis of the relevant literature, is provided. Diagnostic features were highlighted by means of high-resolution digital images and, accordingly, an identification key is given. Trifolium spumosum, T. vesiculosum, T. mutabile and T. setiferum are reported to be distributed throughout Italy. We have updated the Italian distribution of the first three species by providing new occurrences from Tuscany, Umbria, Campania, Basilicata, and Calabria and by correcting previous references. The current presence of T. multistriatum in southern Italy is confirmed by our study, while T. setiferum must be excluded from the flora of Sicily. The study resulted in five new regional occurrences and 16 changes of presence status. Finally, intermediate forms between T. vesiculosum, T. multistriatum and T. mutabile were found both in living material and in the revised herbarium specimens.
Central and southern Italy, clovers, identification key, new records, Trifolium subsect. Mystillus
The genus Trifolium L. is cosmopolitan, with about 255 species occurring mostly in the northern hemisphere (
Based on the more recent classification of the genus, derived from molecular phylogenetic evidence (
There is a wealth of literature on the European Trifolium representatives.
Among the classical studies, the monograph by
Main taxonomical treatments of the Trifolium subsection Mystillus species in Italy.
T. multistriatum W.D.J.Koch | T. mutabile Port. | T. setiferum Boiss. | T. spumosum L. | T. vesiculosum Savi | |
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T. mutabile Port. (T. leiocalycinum Boiss. & Spruner) |
T. setiferum Boiss. (T. rumelicum (Griseb.) Halacsy; T. multistriatum Koch) (provisional) |
T. spumosum L. | T. vesiculosum Savi | |
|
T. mutabile Port. | T. setiferum Boiss. | T. spumosum L. | T. vesiculosum Savi | |
|
T. mutabile Port. (T. leiocalycinum Boiss. & Spruner in Boiss., T. vesiculosum subsp. mutabile (Portenschl.) Ponert.) |
? T. setiferum Boiss. (T. multistriatum Koch, T. rumelicum (Griseb.) Halacsy, T. vesiculosum subsp. multistriatum (Koch) Arcangeli |
T. spumosum L. | T. vesiculosum Savi | |
|
T. vesiculosum var. rumelicum Griseb. (T. multistriatum Koch) |
T. mutabile Portenschl. (T. leiocalycinum Boiss., T. paleaceum Portenschl.) |
T. setiferum Boiss. |
T. spumosum L. (T. apulum Horst ex All.) |
T. vesiculosum var. vesiculosum |
|
T. mutabile Portenschlag. | T. spumosum L. | T. vesiculosum Savi | ||
|
T. vesiculosum subsp. multistriatum (Koch) Arcangeli (T. setiferum Boiss.) |
T. mutabile Portenschl. | T. spumosum L. | T. vesiculosum subsp. vesiculosum | |
|
T. multistriatum Koch (T. setiferum Boiss., T. rumelicum (Griseb.) Halacsy) |
T. mutabile Portenschl. (T. leiocalycinum Boiss.) |
T. spumosum L. | T. vesiculosum Savi | |
|
T. vesiculosum Savi β multistriatum Koch | T. vesiculosum Savi γ mutabile Portschg. |
T. spumosum L. (T. apulum All.) |
T. vesiculosum Savi α typicum | |
|
T. multistriatum Koch |
T. mutabile Portenschlag. (T. leiocalycinum Boiss. & Sprunn.) |
T. setiferum Boiss. (T. vesiculosum var. rumelicum Griseb.) |
T. spumosum L. (incl. T. apulum All., T. argutum Russel.) |
T. vesiculosum Savi |
|
T. mutabile Portenschl. (T. multistriatum Koch, T. vesiculosum Reich. non Sav., T. setiferum Boiss.) |
T. spumosum L. (T. apulum All.) |
T. vesiculosum Sav. |
Currently, T. mutabile Port., T. setiferum Boiss., T. spumosum, and T. vesiculosum have been reported within the Italian territory and regarded as distinct species, while T. multistriatum W.D.J.Koch has either been completely ignored (
The gaps in knowledge and doubts indicated in the reports over the years concerning the units of the group clearly denote their problematic identification. More specifically, ‘Flora d’Italia’ (
This paper is part of a broader research aimed at updating the distributional range and taxonomy of the Italian clovers. In particular, the aim of this study was to provide new chorological data on T. subsect. Mystillus, in the light of the new findings from central and southern Italy, the recent re-evaluation of T. multistriatum, field surveys, revision of herbarium specimens, and literature analysis.
This study is based on analysis of relevant literature, including protologues, field surveys and examination of herbarium specimens kept in
We collected flowering and fruiting samples of Trifolium multistriatum, T. mutabile and T. vesiculosum from May 2015 to July 2016 in several central and southern Italian regions (for the collection sites refer to the collected specimens). Geographical coordinates, when indicated, are in the form of Decimal Degrees (DD) as defined by the World Geodetic System of 1984 (WGS84). The study involved the acquisition of high-resolution digital images of floral details from fresh and dried material, useful for species identification and comparison. Morphological observations were done under a Leica M60 stereomicroscope, using a Leica IC80 HD Digital camera. The images were processed by means of the application LAS V-3.8. Plants from some of the sampled populations were cultivated in pots and seeds were stored for further studies.
The geographical arrangement of each species involved in this study has been updated. It refers to the Italian administrative regions and uses the following symbols, according to
Based on our observations of fresh and dry material and of several digital images, we found that the following characters are crucial for the identification of Trifolium subsect. Mystillus species occurring in Italy: shape of flowering and fruiting heads, corolla/calyx ratio, shape of the calyx tube and teeth, consistency and thickness of the fruiting calyx, presence/absence of prominent longitudinal nerves and transverse veins in the fruiting calyx, and leaflets shape of the lower leaves.
The studied clovers are annual species with a spring-summer cycle, inhabiting grassy places among shrubs, roadsides, field margins and other dry fallow lands. Trifolium spumosum is the earliest species, flowering in April-May. It is easily recognizable by its smaller size, highly branched, prostrate or sub-erect stem, small flower heads, and corollas slightly protruding from the calyx. The vegetative parts of T. multistriatum do not differ from those of T. vesiculosum and T. mutabile in the case of vigorous plants and when grown in fertile soil. The latter species, more thermophilous and xerophilous, often appears with plants of very small size. All these species are glabrous, with many erect or ascending stems, rather long-petioled lower leaves, short-petioled to sub-sessile upper leaves, elliptical, acute, serrulate-dentate and mucronulate leaflets. They have many flower heads, which are terminal and axillary, globular to elongate in fruit (Figure
The study resulted in five new regional occurrences and 16 changes of presence status.
(holotype indicated by
Heads large; fruiting calyx ovoid with thick, longitudinal nerves all along, closed-spaced, transverse veins slightly visible; corolla > than twice as long as the calyx tube, seeds ovoid, light brown and dark mottled (Figures
Friuli Venezia-Giulia: 0A, Liguria: 0A, Campania: + (new), Basilicata: + (new), Calabria: + (new), Sicily: - (new).
The identity and autonomy of the name Trifolium multistriatum compared to the other species with whom it is closely related is discussed by
The delimitation, status and distribution of T. multistriatum, with respect to T. setiferum and to T. vesiculosum var. rumelicum, is still under debate (see also
The sole report of this species from Sicily (provisionally treated as T. setiferum by
Italy. Campania: Aquilonia, nei pressi del Fiume Ofanto, 40.963606°N. 15.557549°E, 339 m, 22 June 2016, A. Scoppola and E. Lattanzi (
(holotype indicated by
Heads large, fruiting calyx tubular, longitudinal nerves barely visible in the distal portion; corolla > than twice as long as the calyx tube, seeds irregularly ovoid, light brown (Figures
Liguria: 0A, Tuscany: +A (new), Umbria: +A (new), Lazio: +A (new), Campania: 0 (new), Apulia: +, Basilicata: 0 (new), Calabria: +, Sicily: +.
Species endemic to the Mediterranean area (
Here, we report it for the first time in central Italy both in the countryside south of Manciano (Grosseto), where it was found to be abundant in fallow and resting fields as well as wood edges, and in the outskirts of Castel Giorgio and of Orvieto (Terni), not far from the Lazio border, where it was observed in small populations of fallow fields and roadsides. In both stations, together with the one recently reported in Lazio (
Trifolium mutabile is known in Campania (
Finally, the current presence of T. mutabile in Basilicata (
Italy. Tuscany: Manciano, strada sterrata verso il Pod. Il Pelargone 42.538296°N 11.543912°E, 253 m, 26 May 2016, A. Scoppola (
(holotype indicated by
Heads small; fruiting calyx inflated, calyx teeth with ciliolate base; longitudinal veins numerous; corolla longer than calyx. Seeds brown (
Calabria: - (new), Sicily: - (new).
Described from the Province of Izmir in Turkey, it is probably an eastern Mediterranean endemic naturally occurring only in Turkey and Greece, although many sources suggest it has a wider distribution based on its assumptive synonymy with T. rumelicum and/or T. multistriatum. We agree with
(lectotype designated by
Flowering heads small (15-20 mm); fruiting calyx vesicular-turbinate, netted-nerved; corolla short, slightly protruding from the calyx (Figure
Liguria: 0 (new), Tuscany: 0 (new), Marche: 0, Lazio: +, Abruzzo: 0 (new), Campania: 0 (new), Apulia: 0 (new), Basilicata: 0 (new), Calabria: +, Sicily: +, Sardinia: +.
It is a widespread steno-Mediterranean thermophilous and xerophilous species, especially found in dry uncultivated lands of coastal areas. It was described on the basis of collections made in Italy and France. Based on our data, the distribution in Italy is very fragmented and in decline, especially in the central regions. A similar depletion has been reported in southern France where the species is classified as naturalized over most of the territory (
The Apulian material dating back to the 1970s, deposited in
(‘lectotype’ designated by
Flowering heads large; fruiting calyx vesicular, turbinate, shining, netted-nerved, calyx teeth with base not ciliolate; corolla longer than calyx, seeds sub-globular, light brown (Figures
Tuscany: +, Umbria: +, Lazio: +, Abruzzo: +, Campania: +, Apulia: 0 (new), Basilicata: 0 (new), Calabria: 0 (new), Sicily: 0 (new), Sardinia: +.
It is a Mediterranean species growing from southern to central Europe on fertile, well-drained soils. This clover is cultivated on a large scale for forage and has a good ability of self-sowing because of the high production of hard seeds (
This species is considered as occurring in Calabria by
The presence of the species by
Italy. Tuscany: Manciano, Monti di Castro Loc. Campigliola, 42.526919°N 11.519618°E, 27 June 2015, A. Scoppola (
1 | Fruiting calyx inflated, more or less vesicular, turbinate and shining (Figure |
2 |
– | Fruiting calyx tubular or oblong to ovate, not or slightly inflated, opaque and rigid, never vesicular (Figure |
3 |
2 | Flowering heads small (15–20 mm), ovoid; bracts broad and shorter than the calyx tube; standard slightly protruding from the calyx (< than twice the tube length), straight after anthesis; leaflets obovate to rhombic, truncate to retuse at apex | T. spumosum |
– | Flowering heads larger, dense, bracts narrower and as long as the calyx tube; standard longer than calyx (≥ than twice the tube length), deflexed after anthesis; leaflets elliptic to obovate, acute, mucronulate | 4 |
3 | Calyx tube oblong, cylindrical, not narrowed at throat in fruit, with longitudinal veins slightly visible only in the distal portion (below the teeth) | T. mutabile |
– | Calyx tube ovoid, slightly narrowed at throat in fruit, with many longitudinal, thick nerves all along, generally very closed spaced; transverse veins not visible or slightly, thick and forming very small and regular meshes | T. multistriatum |
4 | Calyx teeth lanceolate-subulate with base not ciliolate, fruiting tube vesicular, turbinate, shining, clearly netted-nerved, with wide meshes; terminal heads larges (25–45 × 20–35mm), globular to ovate, elongating in fruit; leaflets large, elliptic, acute or mucronulate | T. vesiculosum |
– | Calyx teeth subulate-setaceus, with base ciliolate; fruiting tube inflated, white, thin walled, not vesicular; longitudinal veins numerous, transverse ones slightly visible; terminal and axillary heads smaller (20–25 × 15–20), ovate-globular to ovoid in fruit; leaflets obovate-cuneate with a terminal spiny mucro | T. setiferum |
Our study has shown that knowledge on the distribution of clovers belonging to Trifolium subsect. Mystillus in Italy is still largely incomplete. The revision of herbarium samples, the study of all literature data as well as field collections and observations have highlighted that, in many Italian regions, T. vesiculosum and T. spumosum have been reported in the past by mistake or through lack of recent reports; T. setiferum, instead, must be excluded from the national flora (Figure
The delimitation and status of T. multistriatum, with respect to T. vesiculosum var. rumelicum, is to be considered problematic (see also
Based on a careful examination of the floral details of the relevant material of T. multistriatum in
Finally, T. mutabile var. gussoneanum should certainly be re-evaluated, since it is widespread and well characterized at least in Sicily, where neither T. vesiculosum nor T. multistriatum have been confirmed; already in Calabria it appears to be more variable and with transitional forms to T. vesiculosum s.str. or to T. multistriatum and requires confirmation in Basilicata and Campania.
We are grateful to A. Santangelo, P. Medagli, V. Tomaselli, L. Cecchi, R. Marcucci, S. Peccenini, R. Wagensommer, A. Croce, G. Domina, F. Conti, F. Bartolucci, A. Millozza, L. Rosati, R. Galesi, and G. Veronico for useful information; to Directors and Curators of some quoted Herbaria for their support during our visit, for loans or scanned images. We also thank F. Manzano Gutierrez, A. Nizzoli and M. Pellegrino for high-resolution digital images of floral details, to G. Cannata for the online literature review and to F. Bartolucci and two anonymous reviewers for their detailed revisions that greatly improved the manuscript.
Trifolium multistriatum
W.D.J.Koch – ITALY. Friuli Venezia Giulia: Trieste, S. Andrea, August 1840, M. Tommasini (L n. 1997850 digital image!); Trieste, immunizione di Campo Marzio, 29 Jul 1840, M. Tommasini (
Trifolium mutabile
Port. – ITALY. Lazio: Bomarzo, R.N. Monte Casoli, 184 m, 12 June 2009, A. Scarfone (
Trifolium setiferum
Boiss. – TURKEY. Anatolia: Caria, 1843, C. Pinard (
Trifolium spumosum
L. – ITALY. Tuscany: Elba, Rio al Padreterno, 1870, E. Marcucci (
Trifolium vesiculosum
Savi – ITALY. Lazio: Viterbo, Poggio Pelagi, 600 m, 25 July 1997, C. Caporali (