Leopoldia neumannii, a new species from Greece (regions of Ipeiros and Peloponnisos) is described and compared with other species of the genus. Aspects regarding the taxonomic classification of the Leopoldia group are discussed in light of an unresolved taxonomic situation within the Muscari sensu lato group.
Version of record first published online on 5 September 2017 ahead of inclusion in September 2017 issue.
Muscari Mill, sensu lato (s.1.) is a genus of Asparagaceae (Scilloideae, Asparagales; APG IV 2016) with about 70 species distributed in Europe, the Mediterranean and W Asia (Garbari & Greuter 1970; Speta 1998; Govaerts 2016). While the centre of diversity is situated in Turkey with 36 documented Muscari s.l. species (Yildirim 2016), ten Muscari sensu stricto (s.str.) and six Leopoldia Parl., species are recognized for Greece (Dimopoulos & al. 2013). During the last decades, several new species have been described (e.g. Ruiz Rejón & al. 1985; Eker & Koyuncu 2008; Jafari & Maassoumi 2011; Jafari 2012, 2015; Yildirim 2016), while the taxonomic situation within Muscari s.l. is still enigmatic and of ongoing debate. Contrasting taxonomic concepts have been applied in recent publications (e.g. Dimopoulos & al. 2013; Jafari 2015; Yildirim 2016). At present, the widely accepted classification of the Kew World Checklist (Govaerts 2016) splits Muscari s.l. into three genera (Muscari s.str., Leopoldia and Pseudomuscari Garbari & Greuter), although the basis for this classification remains unclear.
During the last centuries, several taxonomic concepts of Muscari s.l. have been proposed (for reviews see Bentzer 1973; Speta 1982, 1998). One of the more recent proposals was made by Garbari & Greuter (1970), who divided the group into four genera. Those authors, as well as recognizing Muscari s.str., raised M. subg. Leopoldia (Parl.) Peterm. and M. subg. Muscarimia Kostel. ex Los. to generic rank and described Pseudomuscari as a new genus based on karyological evidence, although they included only a handful of species. In addition, morphological characters such as the prominent bluish to violet sterile flowers as well as the more or less zygomorphic fertile flowers with apophyses on the shoulders were used to separate Leopoldia from the other genera (Garbari & Greuter 1970). However, beside those results as a major argument for a multi-generic treatment, Garbari & Greuter (1970) argued that Muscari s.l. would be comparable to the Linnaean sense of the genus Hyacinthus L., which is nowadays widely accepted as split into several genera (e.g. Bellevalia Lapeyr., Brimeura Salisb., Hyacinthella Schur, etc.).
In contrast, Speta (1982, 1989, 1998) and other authors (cf. Davis & Stuart 1980, 1984) favoured treating the group as a single genus (Muscari s.l.), accepting four subgenera: M. subg. Muscari, M. subg. Leopoldia, M. subg. Moscharia (Baker) Chouard (= M. subg. Muscarimia) and M. subg. Pseudomuscari (Losinsk.) D. C. Stuart. Speta (1982, 1989) favoured the “one genus concept”, with a view on several morphological characters shared among all species, e.g. the degree of fusion of the tepals, the alternate arrangement of the anthers, a uniform placentation, as well as the occurrence of sterile flowers. Furthermore, Karlén (1984) found conflicting results in his work on the karyotypes of different Muscari species from Greece, compared to Garbari & Greuter (1970), which Speta (1989) interpreted as further evidence for his one genus concept. Some years earlier, Davis & Stuart (1980) stated in their Flora europaea treatment of Muscari that “the differences between the subgenera are considered to be of a lower order of importance than those that separate Muscari s.l. from Bellevalia and Hyacinthella”.
However, since the late 1980s no further taxonomic treatments of the genus have been proposed. Speta (1982) discussed the typification of the genus Muscari s.l. and also presented a typification of the four subgenera, but his concept was not applied by others, possibly because he published in German. While other genera, such as the closely related genus Hyacinthoides Heist. ex Fabr., have been solved based on molecular phylogenetic methods (e.g. Grundmann & al. 2010), only the systematic position of the genus Muscari within Asparagaceae has been assessed so far by a handful of weakly supported phylogenies (cf. Pfosser & Speta 1999; Pfosser & al. 2003).
Nevertheless, according to Govaerts (2016), 14 Leopoldia species are accepted, although at least seven more species currently treated in Muscari should be considered as belonging to Leopoldia (Böhnert unpubl.). Until a full taxonomic and systematic revision can be presented (ongoing own work), we apply the classification of Asparagaceae according to Govaerts (2016).
Material and methods
Assessment of the new species was made based on fresh and herbarium material taken from cultivated plants propagated vegetatively from plants collected by M. Neumann at the holotype locality in August 2003 (permit: 608/12.05.2003) and the paratype locality in November 2011. Line drawings were made following the digital drawing technique protocol by Coleman (2003). For scanning electron microscope (SEM) images, pollen material was mounted on aluminium stubs and sputtercoated with palladium (SCD 040, Balzers, Liechtenstein). Samples were observed in a Stereoscan 200 SEM (Cambridge, U.K.). Plant material for comparative morphological analyses was taken from the living collection of Bonn Botanic Gardens between 2014 and 2016, as follows: Leopoldia caucasica (Griseb.) Losinsk. from Georgia (GE-0-BONN-22660), 13 May 2015, T. Böhnert 408 (BONN001671!); L. comosa (L.) Parl. from Greece (GR-0-BONN-20087), 24 Apr 2015, T. Bohnert 403 (BONN001672!); and L. tenuiflora (Tausch) Heldr. from Georgia (GE-0-BONN-32107), 22 May 2015, T. Böhnert 409 (BONN001673!). In addition, measurements from different Flora treatments (Chernyakovskaya & al. 1935; Bentzer 1973; Davis & Stuart 1980, 1984) were used to supplement our own measurements, shown in Table 1.
Results and Discussion
Holotype: [originally collected from Greece, administrative region Ipeiros (Epirus), regional unit Ioannina, municipality Zagori, Monodendri, Vikos Gorge, steep cliff N of monastery of Agia Paraskevi, 39°53′N, 20°45′E, 1140 m, Aug 2003, M. Neumann]; cultivated at Bonn Botanic Gardens (GR-0-BONN-28534), 22 May 2015, T. Böhnert 389 (B; isotype: BONN001674).
Diagnosis — Leopoldia neumannii is distinguished from all other Muscari (s.l., including Leopoldia) species in its overall size of more than 50 cm tall. It differs from other Leopoldia species in its remarkably larger inflorescence as well as in its bulb size. It differs from L. comosa (the morphologically closest species) in having bulbs nearly twice as large and in forming many bulbils, whereas L. comosa never forms bulbils. In L. neumannii the hanging leaves are longer and the hooded apex is always wilted before reaching maturity, whereas in L. comosa the more erect leaves are shorter and usually do not wilt at the apex. In L. neumannii the fertile flowers are cylindric and cream-brown, whereas in L. comosa they are rather bellshaped and comparatively darker brown on the perigou tube. In L. neumannii the pedicels are shorter and slightly hanging, forming a cylindric raceme, whereas in L. comosa the longer pedicels of the lower sterile flowers form a pseudo-umbellate termination of the raceme.
Description — Herbs geophytic. Bulbs ovoid to subglobose, 45–50 × 41–52 mm, always with many bulbils; tunics bright brownish cream. Leaves 5–7, hanging, flaccid, linear, attenuate, flat, not channelled, 30–62 cm × 9–17 mm, margin entire, apex with pointed hood (only visible on young leaves, leaf tips wilt before reaching maturity). Scape solitary, rounded in cross-section, 30–57 cm long (45–85 cm long including inflorescence), not distinctly elongating in fruit. Raceme consistently cylindric, 15–28 cm long; axis dark green at base, violet at apex. Fertile flowers (40-)55–65; bract greenish white, minute, c. 1 mm long, membranous; pedicel patent at anthesis, (4-)7–9 mm long, not distinctly elongating in fruit; perigon tube tricolored, cream-green at base, creamish brown at shoulders, cylindric, (5-)7–9 × (3-)4–5 mm, with minute, bright yellow lobes; stamens alternate; filaments adnate along basal ⅓ of perigon tube, free portion of filaments 2–2.5 mm long; ovary c. 3 × 2–2.2 mm; style conic, c. 3 mm long. Sterile flowers (15-)25–30, slightly hanging, upper flowers strongly reduced; bract minute, longer than those of fertile flowers; pedicel bluish violet, 2–10 mm long, shorter at apex of raceme; perigon tube violet, cylindric in larger flowers, globose in smaller ones, 4–7 × 1–4 mm. Fruit a capsule, dehiscing by 3 valves. Seeds black, globose, 2–2.5 mm in diam., surface rugulose. Pollen 29–32 × 21–22 µm, monosulcate, sculpturing foveolate-reticulate.
Phenology — The new species flowers in May and fruits in June and July.
Distribution and ecology — Leopoldia neumannii is documented so far only from two localities, both in Greece: the Vikos Gorge in Ipeiros (the holotype locality) and Mt Lirkio in Peloponnisos (the paratype locality). The species occurs above 1000 m altitude at both localities. In the Vikos Gorge it grows on ledges of steep cliffs with small depressions forming pot-like structures where sediments and to a minor degree humus accumulate.
Conservation status — We categorize the new species as Data Deficient (DD) according to IUCN criteria (IUCN 2012). Further studies are needed for a more accurate classificaion.
Comparison between the diagnostic characters of Leopoldia neumannii and those of the morphologically related species L. comosa (GR-0-BONN-20087), L. caucasica (GE-0-BONN-22660) and L. tenuiflora (GE-0-BONN-32107). Abbreviations: f.f. = fertile flowers; s.f. = sterile flowers.
Eponymy — Leopoldia neumannii is named in honour of its original collector, Michael Neumann, horticulturist responsible for the geophyte collection at the Bonn Botanic Gardens.
Remarks — Individuals of the new species cultivated outside of a pot can reach significantly larger bulb sizes, up to 70 × 75 mm, and single individuals with bulbs more than 100 mm in diameter have been observed. Larger bulb size appears always to be correlated with the formation of many bulbils.
Leopoldia neumannii differs in many characters compared to the morphologically closest species, L. caucasica, L. comosa and L. tenuiflora. Whereas bulbs of L. neumannii can reach sizes of nearly 50 mm long or more and produce many bulbils per growing season, the other species always have smaller bulbs and no or almost no bulbils. Furthermore, the scape is on average about twice as long as that of L. comosa and even longer compared with the other two species (although in some Greek populations of L. comosa plants with scapes up to 100 cm long have been documented; cf. Bentzer 1973). A common character in Leopoldia is the extended and ascending pedicels of the sterile flowers forming a pseudo-umbellate termination of the raceme, which is not the case in L. neumannii and only to a minor degree in L. tenuiflora. Differences between the four species were also found in pollen size. The pollen of L. neumannii appears >10 µm shorter compared to the measurements for L. caucasica, L. comosa and L. tenuiflora by Pehlivan & Özler (2003). However, only two pollen grains were measured for the new species, so this result might not be representative. Further morphological differences between L. neumannii and the morphologically related species are summarized in Table 1.
At the Vikos Gorge locality, plants of Leopoldia comosa have not been found on the cliffs, but occur on the ground in open forest at altitudes below 1000 m, where L. neumannii is always absent (M. Neumann pers. com.). An additional collection of L. neumannii from above 1000 m on Mt Lirkio in NE Peloponnisos (see below) indicates a wider distribution of the new species at a similar altitude to the Vikos Gorge locality. According to observations by the collector (M. Neumann pers. comm.), L. neumannii seems to replace L. comosa at altitudes above 1000 m, where the latter is always absent, indicating allopatric speciation. It can be assumed that, due to some superficial similarities between L. comosa and L. neumannii, the new species has been hitherto overlooked as distinct. Nevertheless, further field observations and herbarium studies are needed to understand the distribution patterns and conservation status as well as the systematic situation in this group and in Muscari s.l. in general.
Additional specimen seen (paratype) — [Originally collected from Greece, administrative region Peloponnisos, regional unit Arkardia, municipality Tripoli, municipal unit Mantineia, Mt Lirkio, above monastery of Agios Nikolaos near Pikernis, 37°40′15″N, 22°24′36″E, 1130 m, Nov 2011, M. Neumann]; cultivated at Bonn Botanic Gardens (GR-0-BONN-39279), 22 May 2017, T. Böhnert 461 (BONN).
The authors would like to thank Michael Neumann (Bonn Botanic Gardens, University of Bonn) for the collection, cultivation and supply of plant material and extensive discussions about geophyte diversity, systematics and taxonomy; Dr Cornelia Löhne (Bonn Botanic Gardens) and Dr Norbert Holstein (Nees institute for Biodiversity of Plants, University of Bonn) for guidance regarding the manuscript; and Julius Jeiter (Nees institute for Biodiversity of Plants) for preparation of the SEM images. We also thank Mario Martínez-Azorin (University of Alicante) and an anonymous reviewer for their comments on an earlier version of this paper.