Contribution to the knowledge of the genus Alchemilla L. (Rosaceae) in the Italian Alps: Carnic, Julian Alps and Pre-Alps

Martini, F.: Contribution to the knowledge of the genus Alchemilla L. (Rosaceae) in the Italian Alps: Carnic, Julian Alps and Pre-Alps. — Fl. Medit. 31 (Special Issue): 241-255. 2021. — ISSN: 1120-4052 printed, 2240-4538 online. This paper aims at improving the knowledge of the genus Alchemilla in the flora of Friulian Alps (North-Eastern Italy). During 15 years of field observations 33 species were verified, while the sites of A. coriacea represent an unconfirmed historical bibliographic data. Alchemilla carniolica, A. filicaulis, A. glomerulans, A. hirtipes, A. propinqua, A. venosula and A. versipila occurred in a single population, whereas A. monticola, A. flabellata, A. connivens and A. xanthochlora were the most common, having more than 40 records on average. The most frequent geoelements were the orophytes, in particular S-European (12 species), the endemic ones, in particular alpics (8) and finally of the Eurosiberian elements (6). The distribution of the genus in the Friulian Alps, reveals that the maximum presence occurs in the western Main Carnic Chain.


Introduction
The knowledge about the genus Alchemilla in Italy and in particular in the Alpine regions had considerable progress in the last decades, especially due to the activity of floristic cartography, which stimulated the study of some critical genres, including Alchemilla (Fröhner & al. 2012;Bovio & Festi 2014;Festi & al. 2015). In this light, the publication of the fundamental monograph of Fröhner (1990), integrated in 2007 by the cartographic work of Kurtto & al., was an important incentive for a modern approach to the study of this genus.
The recognition of the species of Alchemilla is always a very difficult task due the complexity of forms and lack of description of the diacritic framework of some species. This makes the majority of literature data unsuitable for phytogeographic purposes, when they are not checked by a taxon specialist. Experience showed that up to 90% of the collections specimens are erroneously determined (Fröhner & al. 2012) and, as consequence, the deriving bibliographic citations are also erroneous. For these reasons, all the records given here, except for explicit warning, are based

A. alpinula S. E. Fröhner
Observations. According to current knowledge, it has to be considered an endemic species of the mountain-alpine belts of the South-eastern Alps between Garda Lake and Julian Alps. In the Friulian Alps it is currently known only for their eastern part (Julian Alps and one site in the Carnic Alps), where it grows on rocks, scree slopes of small grain size and dry, stony or discontinuous grasslands, preferably on calcareous soils (Fröhner 2012) between (1300)

A. colorata Buser
Observations. Widespread throughout the Friulian Alps between (770) 1300-1900 m, this South-European orophyte grows on stony, moderately dry to little damp, carbonate or sometimes slightly acid soils of alpine grasslands and dwarf shrub communities (Seslerion variae, Rhododendro-Vaccinion

A. crinita Buser
Observations. It grows in the mountain to alpine belts between (600) 1000-2000 m and prefers fresh to moist or even moderately dry, base-rich soils of calcareous grasslands (Seslerion variae) and sometimes in communities of tall forbs (Adenostylion, Rumicion alpini

A. decumbens Buser
Observations. Endemic species of the Alps, it is diffused in the high-mountain-alpine belts between 1500 and 2100 m, where it prefers small-grass coenoses on long snow-covered soils, grasslands, meadows, peat bogs, edges of streams, much more rarely megaforb communities. These records confirmed the citation of Gortani (1981) for Paularo and Coglians mounts, excluding this taxon from the group of chorological doubts as noted in Poldini & al. (2001

A. effusa Buser
Observations. S-European orophyte, so far observed only in the western Carnic Alps between 1500 and 2200 m on fresh and wet soils by surface trapelation, from ± basic to weakly acid soils. It frequents vegetation of springs, banks of streams, shrubs and communities of tall forbs.
Small specimens of other species have been often erroneously attributed to A. exigua, although this taxon, in spite of the specific epithet, may reach the size of related species. The main discriminating characters of A. exigua are the presence of thin flower pedicels and stems, the leaves teeth mostly finely pectinate and the small flowers, usually carried in pseudoumbels, briefly pedicellated, with a very slender hypanthium. (Fröhner & al. 2012

A. filicaulis Buser
Observations. For this Eurosibirian-North American species, only one site on the North-western border of the region is known so far. The most important characters useful to distinguish A. filicaulis are represented by the red colouration of the basal stipules (shared with A. tenuis Buser and A. rubristipula Buser, both absent in Friuli) and by the flowers mostly in pseudoumbels, with elongated pedicels and slender hypanthium.

A. fissa Günther & Schummel
Observations. It can be observed mainly on acid substrates between 1300 and 2300 m, usually in grasslands with long snow cover persistence, scree slopes of fine grain, meadows and grasslands (Nardion, Poion alpinae) and tall forb communities (Adenostylion). For distinctive characters with respect to A. fallax and A. venosula, see Fröhner & al. (2012

A. flabellata Buser
Observations. From the mountain to the alpine belt, between (750) 1000-2300 m, on moderately dry to moderately moist soils, rocky or superficial, rich to poor in bases and at times weakly acid, in lean grasslands, Elyna communities, dwarf shrubs and pine forests (Seslerion variae, Oxytropido-Elynion, Rhododendro-Vaccinion, Erico-Pinion). For the distinctive characters with respect to A. glaucescens see the notes to the latter. Observations. This eurosiberian species grows in the mountain-alpine belts between (950) 1300-2000 m, on humid to wet areas by surface trapelation, silty, euthrophic, base-rich soils in a different type of coenoses: grasslands (Seslerion variae, Nardion, Polygono-Trisetion, Poion alpinae), wet meadows (Cynosurion), peat bogs, banks of brooks (Caricion davallianae, Calthion palustris), tall forbs communities (Adenostylion) and dwarf shrubs (Rhododendro-Vaccinion). Indicated by Poldini & al. (2001) as a chorological doubt, it was later confirmed. The finding on the Cimon di Crasulina also gives credit to the record of Zirnich in Mezzena (1986) for some neighbouring groups of the Carnic Alps (Pal Piccolo, M. Coglians), while the collection on M. Lussari by the same author makes plausible those of Mainardis & Simonetti (1991)

A. glomerulans Buser
Observations. A. glomerulans populates the subalpine-alpine belts with a preference for eutrophic to mesotrophic soils in snowbeds, peat bogs, vegetation of springs, banks of streams and brooks, alpine shrubs, forest fringes. So far the only finding is in the Carnic Alps and thus extends the eastern limit of the species, previously fixed on the Venetian Alps (Festi 2017;Argenti & al. 2019).

A. hirtipes Buser
Observations. It is an alpic endemic species, whose closest sites in the Italian Alps are located in Alto Adige / Südtirol (Festi 2017). It is present from the mountain to subalpine belt in coenoses referable to Polygono-Trisetion and Nardion, Molinion, Filipendulo-Petasition. According to Fröhner (1990), the fairly falcate profile of the lamina teeth represents a more important distinctive character than the abrupt interruption of the hairiness usually towards the half of the stem (from which the specific epithet). Locally it is known only for the following site.

A. impexa Buser
Observations. According to Fröhner & al. (2012), it is an element of the mountain-subalpine belts, widespread throughout the Alps, which grows on humid areas by surface trapelation, silty, base-rich, humic and eutrophicized soils in peat bogs, grasslands, tall forb communities and fine-grained screes, whose broad phytocoenotic spectrum may include Caricion davallianae, Calthion palustris Polygono-Trisetion, Poion alpinae, Adenostylion and Thlaspion rotundifolii. The absence of previous records from our region is likely due to both the knowledge still insufficient, and perhaps the possible confusion with A. effusa (see Fröhner 1990), since A. impexa is reported in the Carinthian Alps (Hartl & al. 1992

A. leptoclada Buser
Observations. The species has a range extending from the Jura Massif (France) to the western Alps. The site of M. Matajur is the only one so far established in Friuli. It would be therefore the most eastern site for the species (see Kurtto & al. 2007), since the nearest known localities are those of the Bergamo Alps reported in Fröhner & al. (2012) and in . Moreover, some indications of A. alpina s.latiss., such as those of Minio and Crichiutti in Gortani & Gortani (1905-06) by Matajur himself should perhaps be ascribed to this species. In addition, the close affinity with A. conjuncta, suggests that historical records of the latter may be referred to A. leptoclada (Frohner 1990). A. leptoclada prefers cracks in cliffs, scree slopes with small size grains, nutrient poor grasslands on rocky or shallow soils, mainly on carbonate substrates (Potentillion caulescentis, Seslerion variae). A. alpinula and A. leptoclada are currently the only representatives of the sect. Alpinae in the Friulian Alps.

A. micans Buser
Observations. Eurosiberian species that can be observed from the mountain to the alpine belt at an altitude that ranges between (950)

A. monticola Opiz
Observations. This eurosiberian Alchemilla is one of the most frequent species in the Friulian Alps. It shows a high variability in the hair-covering, with individuals from totally hairless (often confused with A. subcrenata) to densely hairy (confused with A. glaucescens) (Fröhner & al. 2012). In the region, it is found from the (low) mountain to the alpine belt between 800 and 2100 m, generally on moderately dry to humid, eutrophic, base-rich soils. It grows in dry grasslands of Mesobromion and Seslerion variae, relatively wet meadows (Poion alpinae, Polygono-Trisetion, Cynosurion,), banks of brooks (Calthion palustris) and forest fringes (Adenostylion  Carnizza, m 1110Carnizza, m , 9646/3, 8.7.2011Vers N del M. Matajur, presso Casere Tu v Dolin, m 1435, 9747/3, 14.8.2008.

A. obtusa Buser
Observations. It is an endemic species of the Alps, with only few known sites. In the western Carnic Alps it occurs in the mountain-alpine belts between 1300 and 2000 m. The species prefers wet to humid, loamy, eutrophic, base-rich soils of springs, rivulets (Calthion palustris, Montio-Cardaminetalia), bushes and forest fringes (Adenostylion). It can be confused with specimens of A. glabra with developed haircovering, but A. obtusa is a more slender plant, with light blue-green leaves on the upper surface and mostly rounded teeth and not infrequently in some basal leaves the stipules are fused for 0.5-2 mm at the base (free in A. glabra).

A. propinqua H. Lindb. ex Juz.
Observations. Species of North-eastern Europe, whose Italian sites, disjointed from the main range, were hitherto known only for Trentino (Festi 2017). That of the Val Rauna (near Tarvisio) would constitute to date the eastern limit of the species on the Italian Alps.

A. reniformis Buser
Observations. South European orophyte, is present in the Alps from the Maritime to Styria, as well as on Jura, Fichtelgebirge, Erzgebirge, Sudetes, Carpathians, Northwestern Balkan Peninsula, Bulgaria and Northern Apennines (Fröhner 1990, Kurtto & al. 2007. It grows in the mountain and subalpine belts between 1450 and 1900 m, on soils with variable contents in bases, also subacid, from moist to wet, mesotrophic, in grasslands, meadows and communities of tall herbs (Nardion, Polygono-Trisetion, Adenostylion).

A. strigosula Buser
Observations. It is a South-West European orophyte that in our region is currently known for the western part of the Friulian Alps. The findings corroborate the historical citations of Gortani & Gortani (1905-06, 1981 from Casadorno (Rigolato) and Casera Talm (M. Talm), located a few kilometres SE of M. Neval (see Specimina selecta). It has been observed between 1400 and 2000 m on moderately dry to moist soils, silty, rich in limestone and eutrophic, in grasslands and meadows (Seslerion variae, Polygono-Trisetion).
This species could be easily confused with the closely related A. subglobosa, which has not yet been found in Friuli and which has a dark green colouration, at times suffused with violet, infundibuliform-plicated leaves, strongly wavy at the margin, with deep incisions (25-60%) and globose hypantium, largely rounded at the base, glabrous. A. subglobosa is known for Alto Adige / Südtirol (Wilhalm & al. 2006).

A. subcrenata Buser
Observations. Species with eurosiberian distribution, of the mountain-alpine belts, locally observed between 1100 and 2000 m, it grows in wet to humid soils, silty, rich in limestone or in bases, eutrophic. It is found in grasslands and meadows (Poion alpinae, Polygono-Trisetion), vegetation of springs and in the banks of streams (Calthion palustris), shrubs and forest fringes (Adenostylion).

A. tirolensis Buser ex Dalla Torre & Sarnth.
Observations. Orophyte of the Eastern Alps with disjunction on the Swiss Jura (Hügin & al. 2009), has recently been removed from the category of species indicated by Poldini & al. (2001) as chorological doubts.

A. undulata Buser
Observations. Endemic to the Alps and the northern and central Apennines, the species appears on the mountain-alpine belts between (1300) 1600 and 2300 m. It is found on humid to wet, humic and base-rich soils, eutrophic, in different habitats: grasslands and meadows (Poion alpinae and Polygono-Trisetion, for instance), humid environments (Calthion palustris, Caricion ferrugineae), forest fringes (Adenostylion), communities of tall herbs of alpine huts (Rumicion alpini).
Small specimens may be confused with A. decumbens, but the latter is recognizable because usually has less developed hair-covering particularly on the leaf page and the basal leaves have fewer teeth and are never stellate.

A. venosula Buser
Observations. It is a widespread species in the Alps, from the Bergamasque Alps to the Karavanks, it populates the mountain-alpine belts in wet to humid, silty, seldom weakly acid, mesotrophic, base-rich soils. Currently in the Friulian Alps is known only for the site indicated below. For a comparison of characters among other morphologically related species (A. connivens, A. fallax, A. fissa) see the tables in Fröhner & al. (2012).

A. versipila Buser
Observations. It is a species diffuse especially on the northern slope of the Alps and on the southern Jura (Fröhner & al. 2012). It grows particularly on calcareous soils in grasslands, scree slopes of small grain size, forest fringes. The collection site lies at a short distance from the border with Carinthia, making it plausible that even the sample of uncertain attribution collected at Mauthner-Alm (Fröhner 1990) may be referred here.
The difficult distinction from A. glabra makes the collection and careful review of samples essential (Festi 2017

Discussion and conclusion
The genus Alchemilla in the Friulian Alps is currently encompassing by 33 species, to which is added A. coriacea of which exists an unconfirmed historical bibliographic data of Gortani (1981) for M. Varmost (Carnic Alps).
The most represented sections are sect. Alchemilla with 12 species and sect. Plicatae with 7 species. Alchemilla carniolica, A. filicaulis, A. glomerulans, A. hirtipes, A. propinqua, A. venosula and A. versipila occurred in a single population, while A. monticola, A. flabellata, A. connivens and A. xanthochlora were the most common species, having more than 40 records on average.
From the chorological point of view, we observe the predominance of the orophytes, in particular South-European (12 species), of the endemic, in particular alpics (8), and finally of the Eurosiberian elements (6).
The distribution of Alchemilla species richness in the Friulian Alps (Fig. 1), even if still lacking in some zones, reveals that the maximum number of taxa occurs in the western Main Carnic Chain, where a maximum of 13 species is reached in the quadrants 9444/1 (M. Paularo) and 94443/1 (M. Crostis). Southernmost, similar values are found in the quadrants 9443/4 (M. Zoncolan), 9543/2 (Group M. Arvenis-Tamai) and 9542/3 (M. Tinisa). In the Julian Alps the highest values are found in the quadrants 9546/4 (Jof di Montasio-Jof Fuart groups), 9646/2 and 9646/3 (Group of M. Canin). In the Julian Pre-Alps the maximum value is reached on M. Matajur (9747/3), while on the Carnic Pre-Alps the peak can be observed on the chain M. Duranno-M. Borgà (9640/3, 9740/2). This distribution pattern indicates some gaps to fill, the most meaningful of which concerns the group of the M. Cavallo of Pordenone, that it still appears insufficiently investigated.
However, as Fröhner & al. (2012) pointed out, while along the northern foot of the Alps many species penetrate deeply into the Alpine foreland, descending at very low altitudes, on the southern Alps, in particular in the pre-alpine sectors, this occurs with low frequency. As well as in the mountains of the Lombard Pre-Alps, also in Friuli the limit of southern diffusion of the genus seems to stop in the mountain belt around the 900-1000 m, with descents at lower altitudes in the northern slopes. A further limit to the diffusion of Alchemilla in Friuli is linked to the scarce diffusion of siliceous substrata, which favour the formation of humid environments (springs, banks of brooks, marshy areas, humid meadows, alder and willow shrubs, etc.). In fact, humid habitat represent the ecological optimum for many species (e.g A. acutata, A. effusa, A. glabra, A. micans, A. subcrenata, A. xanthochlora, etc.). On the other hand, the large diffusion of carbonate substrates in the pre-alpine area, with their high permeability, represent a limiting factor together with the lowering of the less average altitudes. Species linked to carbonate substrates are considered for example A. alpinula, A. colorata, A. crinita, A. flabellata and A. leptoclada.
On the eastern side of the Region (Natisone Valleys) the wide diffusion of the sandstone substrata and the presence of wet ravines, itself favourable to the presence of Alchemillae, is contrasted by the relatively modest altitude and the diffusion of woods, whose expansion in recent decades has been greatly facilitated by the abandonment of the management of meadows and pastures.