Allium therinanthum C.Brullo, Brullo, Fragman, Giusso & Salmeri, 2014

Allium therinanthum C.Brullo, Brullo, Fragman, Giusso & Salmeri View in CoL , sp. nov. ( Figs. 1 View FIGURE 1 , 2A–B View FIGURE 2 )

Allium tardiflorum similis sed bulbis minoribus, foliis 4, brevioribus, semicylidricis, spathae valvis oppositis, liberis, floribus minoribus, tepalis minoribus, subaequalibus, antheris luteis, minoribus, rotundatis apice, ovario scabrido, capsula concolor, obovoidea, breviori, differt.

Type:— ISRAEL. Mt. Hermon southern slope , at 1500 m elevation, in the Quercus boissieri underwood, UTM coor. 759798/ 3686899, 31 July 2012, S. Brullo, O. Fragman-Sapir & G. Giusso del Galdo s.n. (holotype, CAT! ; isotypes, CAT! , HUJ! ).

Bulb ovoid-sub-globose, 10–30 × 8–25 mm, with outer tunics coriaceous, brown-blackish and inner ones membranaceous, whitish. Stem 25−40 cm tall, cylindrical, glabrous, erect, covered by leaf sheaths for 2/3–3/4 of total length, inserted externally to the bulb. Leaves 4, green, glabrous, with blade 8−20 cm long, 2–3.2 mm wide, semi-cylindrical, fistulous, with prominent ribs. Spathe persistent, with two valves unequal, opposite, erect to suberect, much longer than the inflorescence, the larger 7-nerved and 8−12 cm long, the smaller 5-nerved and 4−8 cm long. Inflorescence lax and fastigiate, 20−50 flowered; pedicels erect, unequal, 10−30(–60) mm long. Perigone campanulate, with tepals equal, whitish to straw coloured, tinged with purplish, elliptical, rounded at the apex, 5−5.5 × 2−2.2 mm wide, midrib purplish-green. Stamens included in the perigone or subequal, with simple filament, white, unequal, the outer ones 2.2−2.5 mm long, the inner ones 2.8−3.2 mm long, connate below into an annulus 1.5−1.6 mm high; anthers yellow, oblong, 1.1 × 0.8 mm, rounded at the apex. Ovary sub-cylindrical, and slightly throttled in the middle and at the apex, greenish-yellow, densely roughish above, 4−4.2 × 2−2.2 mm; style white, 0.4−0.6 mm long. Capsule trivalved, obovoid, green 4.5−5.5 × 4.5−5 mm.

Additional specimens seen (paratypes):— ISRAEL. N. Israel, Mt. Hermon 1700 m a.s.l., 17 July 2013, O. Fragman-Sapir s.n. ( CAT!, HUJ!) .

Etymology:—The specific epithet refers to the typical flowering behavior (late summer), from the ancient Greek “ therinos ” (= in summer) and “ anthos ” (= flower).

Distribution and ecology:— Allium therinanthum is localized at the mountain belt of southern slopes of Mt. Hermon (northern Israel), where it grows on calcareous rocky stands at ca. 1500 − 1700 m of elevation. It is found in shady sites, usually under the canopy of open Quercus boissieri Reut. in Boissier (1853: 119) woodlands. Actually, such micro-habitats act as refugia, being sheltered from solar radiation, and thus allowing to this geophyte to overcome the harsh summer drought which characterizes this territory. Generally, it has to be noted that woodland environments are usually preferred by late flowering garlics, such as A. tardiflorum .

Leaf anatomy:—The leaf cross section of Allium therinanthum shows a semi-circular outline, provided with 7−9 prominent ribs in the abaxial and flat in the adaxial face. The epidermis has small cells, with the exception of the ribs where cells are bigger, and it is covered by a thin cuticle. Stomata are numerous and distributed along the whole leaf perimeter. The palisade tissue is regular and compact, and arranged in one layer of short cylindrical cells. The spongy tissue is fairly thin, since the leaf appears widely fistulous. Many secretor canals occur under the palisade tissue. The vascular bundles are 24−26, 13−14 of which occupy abaxial position, with some of bigger size at the ribs, and 11−12 small ones adaxial position ( Fig. 3A View FIGURE 3 ).

Karyology:— Allium therinanthum has a diploid chromosome complement ( Fig. 4A View FIGURE 4 ) with 2n = 16. The karyotype is fairly regular and mostly consists of metacentric chromosomes, except two meta–submetacentric pairs (msm: arm ratio exceeding 1.3) which are microsatellited on the short arms. Other microsatellites were observed on the short arms of some metacentric chromosome pairs ( Fig. 4B View FIGURE 4 ). The karyotype formula can be resumed as 2n = 2x = 16: 4m + 8m sat + 2msm + 2msm sat. Absolute chromosome length ranges from 14.76 ± 3.7 µm for the longest chromosome to 9.52 ± 1.1 µm for the shortest, while the relative length varies from 7.81 ± 1.5% to 5.08 ± 0.4%. Chromosome measures and symmetry indices ( Table 1 View TABLE 1 ) point at a relatively high degree of homogeneity and symmetry of the A. therinanthum karyotype.

Conservation status:—At present, the populations of Allium therinanthum does not seem to be particularly threatened by human activities, being located within a military area that is also a protected reserve, i.e. "Hermon Nature Reserve". However, increasing cattle grazing in the past several years causes many plants to be crushed. The known populations consist of estimated 5000 individuals. Considering the very narrow range of the species, we suggest to add it to the Red List of Threatened Species as Endangered. Thus, based on the IUCN criteria (2010), it is proposed its inclusion in the following category: EN B2b(ii, iv).

Taxonomic relationships:—According to literature, several late flowering species of Allium sect. Codonoprasum have been described mainly over the last decades, and they are widely distributed in the whole Mediterranean area, but particularly in the eastern sector. The species occurring in the western Mediterranean are all tetraploids (2n = 32), and they are usually found in damp soils of salt marshes or ponds, such as A. savii Parlatore (1857: 554) from N Italy, Corsica, Sardinia, France and Baleares (Brullo et al. 1997c), and A. telmatum Bogdanović et al. (2009: 85) from Croatia, as well as in shady rocky stands, such as A. oporinanthum Brullo et al. (1997a: 297) from SE Spain and S France, or in undergrowth, such as A. anzalonei Brullo et al. (1997b: 34) from central Italy. Whereas, the eastern Mediterranean species are more numerous and they are mostly diploid (2n = 16), with the only exception of A. apolloniensis Biel et al. (2006: 367) from Sifnos island which is tetraploid (2n = 32). The other eastern autumnal species are: A. autumnale Davis (1949: 113) from Cyprus, A. tardans Greuter & Zahariadi in Zahariadi (1975: 51) from Crete and Karpathos, A. rausii Brullo et al. (2003b: 136) from Thessaly ( Greece), A. platakisii Tzanoudakis & Kypriotakis (1993: 309) from Pondikonisi islet, A. euboicum Rechinger (1961: 435) from Evvoia, A. aegilicum Tzanoudakis (2000: 81) from Antikithira islet, A. archeotrichon Brullo et al. (1999: 42) from Rhodos, A. tardiflorum from Israel, A. brussalisii Tzanoudakis & Kypriotakis (2008: 141) from Sterea Hellas ( Greece), A.makrianum Brullo et al. (2010: 270) from Chios island.

From the morphological point of view, Allium therinanthum is well differentiated from the above-mentioned species especially for a series of character-state combinations that allow a clear separation of all of them. In particular, A. therinanthum , for some features regarding the habit, inflorescence and flowers, shows closer relationships with A. tardiflorum , a punctiform endemism occurring in Israel, too ( Figs. 2D View FIGURE 2 , 5 View FIGURE 5 ). However, A. tardiflorum is characterized by larger bulbs, with outer coats membranaceous and purplish-violet, leaves more numerous and longer, sub-cylindrical, without ribs, shorter than stem, spathe valves unilateral, almost completely fused, the shorter one 3-nerved, tepals yellow-green tinged with purple, longer and markedly unequal, anthers longer, white-yellow, ovate and apiculate, occurrence of interstaminal appendices, ovary shorter, ellipsoid, minutely papillose above and capsule subglobose. Besides, A. tardiflorum behaves as a typical autumnal flowering species (late September-early November), and it grows at a lower elevation (ca. 400−500 m a.s.l.) in pine-woods dominated by Pinus halepensis Miller (1768 : without pagination). From the karyological analysis, this species revealed a somatic chromosome number of 2n = 2x = 16 in all examined samples from the type locality ( Fig. 6A View FIGURE 6 ). This is the first karyological report for A. tardiflorum . Although both taxa share the same chromosome set, the karyotype of A. tardiflorum is very different from that one of A. therinanthum given that it is characterized by two subterminal chromosome pairs provided with long linear satellites on the short arms, while the remaining chromosomes are more or less metacentric, with an arm ratio ranging from 1.04 to 1.2 ( Fig. 6B View FIGURE 6 ). The chromosome formula of A. tardiflorum can summarised as 2n = 2x = 16: 12m + 4st sat. In addition, chromosome size in A. tardiflorum is smaller than in A. therinanthum : chromosomes range from 12.22 ± 1.9 µm to 7.20 to ± 1.7 µm. The leaf anatomy also shows relevant differences, because the leaf cross section of A. tardiflorum ( Fig. 3B View FIGURE 3 ) has a subcircular to elliptical and smooth outline, an epidermis covered by a thicker cuticle, with regular cells and more stomata, less (max. 20) and often larger vascular bundles. Besides, A. therinanthum can be confused with A. galileum especially for its habit; the latter is a species rather common in Israel, usually occurring at lower elevation (200−1000 m a.s.l.). According to Brullo et al. (2008b), A. galileum ( Fig. 2C View FIGURE 2 ) differs morphologically from A. therinanthum in having bulbs usually smaller (max. 22 × 18 mm), 5−6 leaves, spathe valves completely reflexed, effused-subglobose, pedicels 30−70 mm long, tepals apiculate, greenish-yellow, tinged with brown, stamen filaments purplish, shorter (the inners max. 2.5 mm long), occurrence of interstaminal teeth, and ovary papillose above, 3.2−3.8 mm long. Other differences chiefly regard the karyotype structure, since A. galileum has 8 metacentric chromosomes and one microsatellited pair. Finally, A. galileum flowers earlier (late April to June), and usually grows in open sunny stands.