Allium iatrouinum Trigas, 2017

Trigas, Panayiotis, Kalpoutzakis, Eleftherios & Constantinidis, Theophanis, 2017, Two new Allium (A. sect. Cupanioscordum, Amaryllidaceae) species from Greece, Phytotaxa 297 (2), pp. 179-188 : 180-183

Allium iatrouinum Trigas , sp. nov. ( Fig. 1 )

Related to A. hirtovaginatum and A. pycnotrichum , from which it differs in the following morphological characters: remnants of leaf sheaths on stem covered by patent hairs 1–2 mm long to almost glabrous, spathe 4–5-nerved, flowers usually less than 4 per inflorescence, unequal tepals with the outer 6.5–7.5 mm long, whitish apiculate anthers and a longer tunic neck.Additional differences are presented in Table 1.

Type:— GREECE. West Aegean Islands: Evvia Island, Mt. Ochi, Kerasia summit, c. 10 km N-NE from the town of Karistos at the southern part of the island, rock crevices along the ridge west of the main peak, 1020 m, 38 o 04.919’ N, 24 o 29.755’ E, 4 June 2015 (not in flower, cultivated and flowered on 15 July 2015), Trigas & Adamopoulos 6145 (holotype ACA!, isotype ATHU!).

Bulbs ovoid, clustered, 10–17 × 7–9 mm, with brown tunics, reticulate-fibrous, slightly detached from the base of the bulb, covering the stem up to 6 cm. Stem erect-ascending to erect, flexuous, 13–16 cm tall, covered by the leaf sheaths for 3/4–4/5 of its length. Leaves 3–4, filiform, subcylindrical, 12–19 cm long, covered with patent hairs 1–2 mm long to almost glabrous, much exceeding the inflorescence. Inflorescence fasciculate, unilateral, with (1–) 2–3 (–4) flowers on unequal pedicels 10–18 mm long. Spathe 1-valved, longer to slightly shorter than the inflorescence, 4–5-nerved, 12–26 mm long. Perigone cylindrical-campanulate; tepals pinkish with a darker greenish-purple mid-vein, the outer 6.5–7.5 × 1.5–2.0 mm, oblong, wider at the middle, the inner 6.0–7.0 × 0.8–1.2 mm, narrowly oblong, wider at the upper part, shortly and irregularly dentate at the apex, slightly shorter than the outer. Stamens included in the perigone; filaments narrowly triangular, two-coloured, lemon yellow at their lower half and white at their upper half, the inner 3.0– 3.4 mm long and the outer 1.2–2.5 mm long, connate below into an annulus ca. 0.8 mm high; anthers whitish, oblong, narrowing towards apex, apiculate, 1.0 × 0.5 mm. Ovary yellowish-green, subglobose, smooth, 1 mm in diameter. Style white, 1.5–2.5 mm long. Capsule trivalved, subglobose, 2.5–3.5 mm in diameter.

Etymology:—The species is named after Gregory Iatrou, Professor of Plant Systematic and Phytogeography at the University of Patras.

Karyology:—Individuals of A. iatrouinum collected from the type locality have been investigated karyologically and the constant chromosome number of 2n = 14 was found in all the metaphase plates examined ( Fig. 3 ). Thus, the species is diploid and its chromosome complement consists of six pairs of metacentric chromosomes and one pair of subtelocentric chromosomes satellited in the short arms ( Fig. 3 ). Similar karyotypes have also been observed in other dysploid members of A. sect. Cupanioscordum, i.e., A. ritsii , A. meikleanum , A. pelagicum , A. maghrebinum and A. tingitanum ( Iatrou & Tzanoudakis 1995, Brullo et al. 2015).

Distribution:— Allium iatrouinum is currently known only from the type locality in the southern part of Evvia Island (West Aegean, Greece) ( Fig. 2 ). It is distributed along the ridge that connects Kerasia peak with a lower peak to the west. It is possible that the species has a wider distribution in the area of Cape Kafireas (Cavo d’ Oro). The mountainous area of Cape Kafireas is not easily accessible and its flora remains poorly explored. Two other members of A. sect. Cupanioscordum are distributed in southern Evvia: A. karistanum Brullo et al. (1997: 760) is very local in coastal areas close to the town of Karistos and A. tzanoudakisanum , an endemic species of the Aegean Islands and Peloponnisos, also grows on Mt Ochi. Both these species are diploid with 2n = 2x =16 chromosomes.

Habitat and ecology:— Allium iatrouinum grows in crevices of metamorphic rocks at 1000–1050 m a.s.l. It flowers from the end of June to the end of July. The plants grow in clusters and form groups of ca. 10–20 individuals. The whole area is exposed to strong north winds, especially during the summer. The accompanying taxa of A. iatrouinum are, among others, Inula candida Linnaeus (1753: 862) Cass. in Curvier (1822: 554) subsp. limonella ( Halácsy 1902: 23) Rechinger (1936: 635) , Cerastium candidissimum Correns (1909: 171) , Ballota acetabulosa ( Linnaeus 1753: 584) Bentham (1834: 595) , Thymus longicaulis Presl (1826: 37) subsp. chaubardii ( Reichenbach 1857: 37) Jalas (1980: 323) and Ornithogalum narbonense Linnaeus (1756: 15) .

Conservation:—The single known population of Allium iatrouinum occupies an area of ca. 0.7 ha. Within this small area 23 clusters of individuals were counted and the estimated population size is about 200–400 mature individuals. We presume that additional populations of this tiny, late flowering species will be found in neighbouring areas after careful field work. The distribution area of A. iatrouinum is included in the protected area of the Natura 2000 network “Oros Ochi–Kampos Karystou–Potami–Akrotirio Kafirefs–Paraktia Thalassia Zoni” (GR2420001). The protection status of the area, however, has not prevented the installation of dozens of wind parks that include several hundred of wind turbines. A wind park is also under construction in the distribution area of A. iatrouinum and threatens with extinction the only known population of the species.

Figures

FIGURE 1. Allium iatrouinum sp. nov. (A) leaf sheaths with patent hairs, (B) individuals with immature flowers in their natural habitat, (C) bulb with reticulate-fibrous tunics and a long neck covering the lower part of the stem, (D) inflorescence with side view of the flowers, and (E) flowers, face view.

FIGURE 2. Total known distribution of Allium iatrouinum (blue cycle), A. pycnotrichum (red cycle) and A. ritsii (green cycle).

FIGURE 3. A metaphase plate of Allium iatrouinum, 2n = 2x = 14 (scale bar = 10 μm).