Allium kyrenium Giusso, C.Brullo, Brullo & Salmeri, 2015

Galdo, Gianpietro Giusso Del, Brullo, Cristian, Brullo, Salvatore & Salmeri, Cristina, 2015, Allium kyrenium (Amaryllidaceae), a new species from Northern Cyprus, Phytotaxa 213 (3), pp. 282-290 : 283-287

Allium kyrenium Giusso, C.Brullo, Brullo & Salmeri sp. nov. ( Figs. 1 , 2 )

Allio stamineo similis sed exterioribus tunicis bulbi albo-brunneis, scapo 6−12(15) cm alto, foliis viridi-glaucescentibus, brevioribus, subcylindricis, spathae valvis brevioribus, pedicellibus max. 2 mm longis, floribus brevioribus (3,2−3, 5 mm), tepalis angustioribus (1,6–1,8 mm), filamentis staminorum max. 4, 5 mm longis, antheris stramineis, brevioribus, ovario subgloboso, longiore, leviter scabro, stylo purpureo basim versus differt.

Type:— NORTHERN CYPRUS. Kyrenia Range, calcareous rocky cliffs, southern slopes near Buffavento Castle, ca. 700 m a.s.l., cultivated material, 20 June 2014, S. Brullo, G. Giusso del Galdo s.n. ( holotype CAT!, isotypes CAT!, FI!).

Bulb ovoid, 8−12 × 8–10 mm, with outer tunics coriaceous, brown-blackish, tinged with purplish, inner ones membranaceous, whitish. Stem 6−12(−15) cm tall, cylindrical, glaucescent-green, glabrous, erect to erect-ascending, covered by leaf sheaths for 1/2–2/3 of total length. Leaves 3−4, glaucescent-green, glabrous, with blade 8−15 cm long, 1−1.5 mm wide, subcylindrical, not fistulous, with 10−11 ribs. Spathe persistent, with two unequal, opposite, erect valves, usually longer than the inflorescence, the larger 7-nerved and 3−4.5(−6) cm long, the smaller 5-nerved and 1.5−2.5(−3) cm long. Inflorescence lax, 15−25 flowered; pedicels unequal, 6−20 mm long, pendulous at anthesis and erect in fruit. Perigone cup-shaped, with tepals sub-equal, elliptical, rounded at the apex, pruinose, pinkish-white, tinged with purplish, midrib purplish-green, 3.2−3.5 mm long, the outer ones 1.6−1.8 mm wide, the inner ones 1.4−1.5 mm wide. Stamens exserted from the perigone, with simple filaments, almost entirely purplish, unequal, (2.5−) 3−4.5 mm long, below connate into an annulus 0.5−0.7 mm high; anthers pale yellow, oblong, 1 × 0.8 mm, rounded at the apex. Ovary ellipsoid, green, slightly rugose in the upper part, 1.6−1.7 × 1.3−1.4 mm; style purplish below, 0.8−1 mm long. Capsule trivalved, obovoid, green, 3.2−3.4 × 3.2−3.4 mm.

Additional specimens seen ( paratypes):— NORTHERN CYPRUS. Kyrenia Range , calcareous rocky cliffs, southern slopes near Buffavento Castle , 6 July 2013, S. Brullo, G. Giusso del Galdo s.n. ( CAT!) ; Cyprus , Halefka, distr. Kyrenia, 2000 ft., 23 May 1941, P. Davis 3607 ( K!) ; Cyprus , Kythrea, eroded sandstone hills, 25 May 1941, P. Davis 3642 ( K!) .

Etymology:—The specific epithet refers to “ Kyrenia ” mountain range of North Cyprus.

Distribution and ecology:— Allium kyrenium grows in the crevices of Palaeozoic carbonatic rocks of southfacing slopes of the Kyrenia range ( northern Cyprus), at an elevation of 500−900 m ( Fig. 2 ). Based on our field records, herbarium specimens and literature ( Meikle 1985), A. kyrenium occurs in many sites of the above-mentioned mountain range, such as Buffavento Castle, Halevga and Kythrea. As concerns its ecology, A. kyreniun grows in the calcareous outcrops within maquis dominated by Cupressus sempervirens Linnaeus (1753: 1002) and Juniperus turbinata Gussone (1845: 634) .

Leaf anatomy:—Leaf cross section of Allium kyrenum shows a sub-elliptical outline, provided with 10−11 ribs. Epidermis is formed by big cells and covered by a well developed cuticle. Stomata are numerous and distributed along the whole leaf perimeter. Palisade tissue is regular and compact, arranged in one layer of long cylindrical cells. Spongy tissue is compact, provided with many secretory canals under the palisade tissue. Vascular bundles are 10, 5 of which occupy an abaxial position, and 5, usually smaller ones, have an adaxial position ( Fig. 3 ).

Karyology:—The somatic chromosome number of Allium kyrenium ( Fig. 4A ) was found to be 2n = 2x = 16 in all studied samples. The karyotype is quite regular and mostly consists of more or less metacentric chromosomes, with two meta-submetacentric pairs (arm ratio more than 1.30). These latter pairs are microsatellited on the long arms, while macrosatellites can be found in the short arms of the two smallest metacentric pairs ( Fig. 4B ). The karyotype formula can be specified as 2 n = 2x = 16 = 8 m + 4 msat + 4 msmsat. The absolute length of A. kyrenium chromosomes varies from 10.58 ± 0.4 μm for the longest chromosome to 7.23 ± 0.2 μm for the shortest one, with a mean chromosome length 9.11 ± 1.06 μm, while the relative length ranges from 7.26 ± 0.3% to 4.97 ± 0.2%. All measured karyomorphometric parameters ( Table 1) point out the relatively high degree of homogeneity and symmetry of the A. kyrenium karyotype.

Conservation status:—Currently, the populations of Allium kyrenium approximately count no more than 1,000 individuals scattered along the southern slopes of the Kyrenia range. Actually, this species does not appear under threat by human activities, since it occupies rather inaccessible sites; only occasional fires may represent the highest potential risk. Therefore, following the IUCN criteria ( IUCN 2014), A. kyreniun should be classified as “Vulnerable” (VU D1), similarly to many other bulbous endemic plants assessed by Tsintides et al. (2007).

Taxonomic relationships:—Within Allium sect. Codonoprasum , A.stamineum s.l. represents a group taxonomically well differentiated and isolated from the other taxa included in this section of the subgenus Allium . The A. stamineum group is widespread in the eastern Mediterranean area (Balkan Peninsula, Aegean Islands, Anatolia, Cyprus, Syria, Lebanon, Israel and N Egypt), with isolated populations in the Irano-Turanian ( Iran and Iraq) and Adriatic territories ( Croatia and Italy). Several species belonging to this group have been recently studied by Brullo et al. (2007, 2009) and Bogdanović et al. (2008, 2011b), who highlighted the relationships with the other groups of sect. Codonoprasum. As far as A. kyrenium is concerned, many relevant morphological features allow the new species to be differentiated from the typical populations of A. stamineum . According to Brullo et al. (1993, 2007), A. stamineum s.s. is characterized by outer bulb tunics dark brown, stems 25−50 cm tall, leaves green, semi-cylindrical, up to 20 cm long, spathe valves much longer (up to 10 cm), flowers with pedicels up to 4 mm long, perigone campanulate, tepals 5 × 2−2.5 mm, stamen filaments (2.5−) 3−4.5 mm long, almost entirely purplish, anthers yellow, 1.5 mm long, ovary ellipsoid, scabrouspapillose, 1.8−2 mm long, and style white ( Table 2). In contrast, A. kyrenium has outer bulb tunics whitish-brown, stems 6−12(−15) cm tall, leaves glaucous-green, sub-cylindrical, max. 15 cm long, spathe valves much shorter (max. 6 cm), flowers with pedicels 2 mm long, perigone cup-shaped, tepals 5 × 2−2.5 mm, stamen filaments 4−6 mm long, purplish in the upper part, anthers straw-coloured, 1 mm long, ovary subglobose, slightly rugose in the upper part, 1.6−1.7 mm long, and style purplish below. In comparison with the other species of the A. stamineum group occurring in Cyprus ( Table 2), Allium kyrenium clearly shows some affinities with A. cyprium due to its small plant size, glaucous leaves, perigone shape and size. However, many remarkable differences regarding number of spathe nerves, colour of tepals, stamen filaments and style, shape of ovary and capsule are recognized. In addition, the two species considerably differ in their ecological requirements, since A. kyrenium is a thermo-xerophilous geophyte exclusively found in the crevices of carbonatic rocks, never exceeding 900 m of elevation, while A. cyprium is a silicicolous orophyte growing at 1400−1700 m a.s.l. in the undergrowth of mountain pine-woods. With respect to A. lefkarense and A. marathasicum , A. kyrenium is morphologically and ecologically well distinct from these narrow endemic species. Actually, both these species have much higher stems ( 20−45 cm), leaves green, semi-cylindrical, up to 25−28 cm long, many-flowered inflorescence (up to 55−60 flowers), spathe valves 3−5-nerved, tepals greenish to greenish-brown, anthers longer and ovary subglobose-pyriform. Besides, A. lefkarense is a terricolous species occurring in low-land garigues, while A. marathasicum is a synanthropic plant linked to ruderal environments. In addition, other relevant differences can be detected in the leaf anatomy of these species. As illustrated by Brullo et al. (1993), leaves of A. cyprium , A. lefkarense and A. marathasicum are anatomically rather different from those ones of A. kyrenium . In particular, they are characterized by palisade tissue with smaller cells, a higher number of vascular bundles (15−21), more or less fistulous in the central part. As far as karyology is concerned, chromosome features of A. kyrenium comply with karyotypes of most species of A. sect. Codonoprasum, which commonly appear rather regular and homogeneous and mostly consist of metacentric chromosomes with no more than 1 or 2 anisobrachial pairs, msm or sm types ( Tzanoudakis 1986, 1992, Tzanoudakis & Vosa 1988, Karavokyrou & Tzanoudakis 1994, Brullo et al. 2001a, 2001b, 2003c, 2007, 2008). The karyotype of A. kyrenium is very similar to that one of A. cyprium and A. lefkarense with respect to the general chromosome formula and two satellited pairs on the long arms and short arms respectively. Conversely, the karyotype of A. marathasicum is markedly different in either its triploid chromosome complement (2n = 3x = 24) and occurrence of submetacentric pairs ( Brullo et al. 1993). Finally, A. kyrenium can be considered a schizoendemic ( Siljak-Yakovlev & Peruzzi, 2012), whose origin did not involve relevant karyotype modifications, but speciation is likely arisen from geographical isolation. This isolation was certainly favoured by the peculiar substrate (limestones), since all the allied species occurring in Cyprus are linked to siliceous substrata and restricted to the southern part of the island.

Figures

FIGURE 1. Diagnostic features of Allium kyrenium. A. Habit. B. Flowers. C. Perigones and stamens open. D. Pistils. E. Anther. F. Capsules. Illustration by S. Brullo based on living material coming from the type locality.

FIGURE 2. Habit of Allium kyrenium. Photo by S. Brullo.

FIGURE 3. Leaf cross section of Allium kyrenium, from living material coming from the type locality.

FIGURE 4. Chromosome complement (2n = 2x = 16) of Allium kyrenium. Mitotic metaphase plate from type locality (A), arrows indicate satellited chromosomes, and idiogram (B).