Limonium artelariae Koutr., 2024

Koutroumpa, Konstantina, 2024, Limonium artelariae (Plumbaginaceae), a new endemic species and further taxonomic and floristic notes on the genus in the island of Crete, Willdenowia 54 (1), pp. 65-79 : 71-72

Limonium artelariae Koutr. , sp. nov. – Fig. 4A , 5, 7, 8.

Holotype: Greece, Crete, prefecture of Lasithi , beach of the village Vatos , between Myrtos and Tertsa , 34.99686°N, 25.55936°E, rocks and sand, steep, Aug 2014, K. Koutroumpa 300 ( Z [Z-000278447]; isotype: B [ B 10 1161811 ]).

Diagnosis — Limonium artelariae is distinguished from its closely related species in SE Crete, L. cornarianum and L. hierapetrae , by its broadly spathulate, rounded leaves and broadly obovate and wider inner spikelet bracts. Limonium artelariae is rather unique among all other Aegean Limonium endemics for its predominantly tall habit combined with longer and wider, spathulate leaves.

Description — Plants perennial, 48–110 cm tall, glabrous, with several erect stems. Caudices 2–5 cm long, branched with age and then plant with numerous leaf rosettes. Rosette leaves fleshy, light green to glaucous, flat or irregularly folded, rugose to verrucose, (39–)50–165(–210) × 12–43 mm, broadly spathulate, more or less abruptly tapering into petiole, with petiole usually much longer than lamina, margin cartilaginous, sometimes undulate about 0.2 mm wide, apex rounded, mucronate, mucro 0.3–1 mm long, curved backward; 1 central nerve with 2 lateral nerves in large leaves. Stems numerous, erect, usually robust, rugose, branched usually above lower 1/4–1/3; branches very rarely proliferous. Inflorescence trullate to obtrullate in outline; sterile branches absent or 1–3 at lower part of stem, 15–80 mm long, straight; fertile branches straight or slightly arched, erect, directed obliquely upward or spreading. Spikes (12–)15–55(–73) mm long, straight to slightly arched. Spikelets 5.5–6.8 mm long, densely arranged, 3 or 4(or 5) per cm, composed of 2–4(–8) flowers. Outer bract (1.8–)2–2.6 × (1.6–)1.8–2.1(–2.3) mm, glabrous, ovate-triangular, margin broadly membranous, to 0.6 mm wide, apex acute; central part herbaceous, forming a short point. Middle bract 2.2–2.5 × 1.5–2 mm, glabrous, membranous, oblong-elliptic, apex rounded or sometimes emarginate. Inner bract 4.3–5.5 × 3.8–4.5 mm, glabrous, broadly obovate, margin membranous, 0.6– 1.2 mm wide, apex rounded; central part herbaceous, forming a short point to 0.5 mm long, indistinct in mature spikelets. Calyx 4.5–5.5 mm long; calyx tube more or less densely long hairy; calyx lobes 0.5–0.6 mm long, ovate-triangular; tube ribs ending usually above base of lobes. Corolla lilac.

Note — Plant height and leaf size (length and width) measurements were taken from several individuals in the field, at Vatos and Kallikovrechtis (Crete), though not all these individuals were collected as herbarium specimens.

Chromosome number and ploidy — 2 n = 43 (chromosome count by M. Erben (Li-1721) on a cultivated plant of wild source; voucher: FR [FR-0128957]); ploidy level: 5x (inferred from preliminary flow cytometric results of genome size).

Breeding system — Apomixis is inferred from the monomorphic population with self-incompatible pollen-stigma combination B. In addition, the species is of high ploidy level with an odd chromosome number further supporting the view of an apomictic reproduction, following Erben (1978, 1979).

Distribution — Endemic to SE Crete, along the coast between the villages of Myrtos and Tertsa (replaced by Limonium hierapetrae in Tertsa), and at Cape Theophilos at the E edge of Sidonia beach ( Fig. 1 ).

Habitat — Maritime cliffs of marly, calcareous, conglomerate and sandy substrates.

Eponymy — The specific epithet “ artelariae ” honours Dr. Rea Artelari, a former Associate Professor of the University of Patras, Greece, for her invaluable contributions to the systematics of Limonium in Greece and Cyprus throughout her academic career.

Taxonomic notes — The new species is morphologically most closely related to Limonium hierapetrae , which grows in the same area of SE Crete. However, L. artelariae has large, broadly spathulate, rounded leaves compared to the smaller, oblanceolate to oblong-obovate, mostly obtuse leaves of L. hierapetrae . The individuals of the latter are also smaller and have usually narrower, elliptic to oblong-obovate inner spikelet bracts (vs broadly obovate in L. artelariae ; Table 1 ). The dense leaf rosettes with spathulate, sometimes irregularly folded leaves, the densely arranged inflorescences and the obovate shape of the inner spikelet bracts morphologically link L. artelariae to L. cornarianum , which also grows in SE Crete. Further, L. cornarianum is clearly distinguished from L. artelariae by its smaller spikelets and spikelet bracts, and leaves with an acute apex ( Table 1 , Fig. 4 ).

Limonium artelariae is also related to other representatives of the informal taxonomic “ L. sieberi ” and “ L. ocymifolium ” groups sensu Brullo & Erben (2016). Specifically, L. artelariae shows similarities in habit, absence of or very low number of sterile branches, shape of leaves and inflorescences with L. aucheri (Girard) Greuter & Burdet , L. creticum , L. cythereum and L. sieberi also occurring in Crete, and also with L. pigadiense (Rech. f.) Rech. f. from Karpathos and L. ocymifolium (Poir.) Kuntze from the Kyklades. However, several morphological characters clearly separate L. artelariae from these allied species. Specifically, L. aucheri , which has a broad Aegean distribution but occurs in a single locality in NW Crete, is considerably smaller (10–40 cm tall), with narrower leaves (5–10 mm wide) and obovate, narrower inner spikelet bracts (3.2–3.9(–4.1) mm wide; Brullo & Erben 2016). The Cretan endemic L. creticum has partially smaller (20–85 × 5–20 mm), obovatespathulate, obtuse leaves, longer spikelets (6.5–7 mm long) with longer but narrower (6–6.8 × 3.4–3.7 mm) elliptic inner bracts and longer calyces (5.6–6.2 mm long; Artelari 1989b). Limonium cythereum which occurs in Kythira, Antikythira and is newly found in NW Crete, is clearly differentiated by its hairy spikelet bracts ( Artelari & Georgiou 1999; Brullo & Erben 2016). Limonium sieberi is smaller (20–50 cm tall) and has longer spikelets (6.5–9 mm long), inner spikelet bracts (5.2–7 mm long) and calyces (5.2–6.8 mm long; Brullo & Erben 2016). The Karpathos endemic L. pigadiense is also smaller (20–50 cm tall), with narrower (5–15 mm wide), oblanceolate-spathulate leaves, longer spikelets (6.6–7.3 mm long), inner spikelet bracts (5.6–6 mm long) and calyces (5.2–6.5 mm long; Brullo & Erben 2016). And finally, the Kykladean endemic L. ocymifolium is significantly smaller (15–35 cm tall) bearing shorter and somewhat narrower leaves (25–50 × 9–20 mm), mostly longer spikelets (6.5–7.5 mm long), inner spikelet bracts (5.1–5.9 mm long) and calyces (5.2–6 mm long), and significantly wider outer spikelet bracts (2.5–3 mm wide; Brullo & Erben 2016).

Limonium artelariae has the same ploidy level and chromosome number (2 n = 5x = 43) as L. aucheri ( Brullo & Erben 2016) , L. hierapetrae ( Artelari 1989c; Brullo & Erben 2016), L. ocymifolium ( Artelari 1989a; Brullo & Erben 2016), L. pigadiense ( Brullo & Erben 2016) and L. sieberi ( Artelari & Georgiou 2003; Brullo & Erben 2016), while L. cornarianum is probably triploid (see above) and both L. creticum and L. cythereum are hexaploids but with different chromosome numbers (2 n = 6x = 51 and 2 n = 6x = 52, respectively; Artelari 1989b, 1992; Artelari & Georgiou 2003).

Additional specimens seen — GREECE, CRETE, PREFECTURE OF IRAKLIO: Akro Theophilou, calcareniti conglomeratiche, 27 Jun 2002, Brullo & Giusso s.n. (herb. Erben); cultivated from wild source, Akro Theophilou, calcareniti conglomeratiche, 27 Jun 2002, Brullo & Giusso s.n., M. Erben Li-1721 ( B [ B 10 0710890], FR [FR-0128957]); between Kallikovrechtis and Tertsa, 34.98966° N, 25.54750° E, marls and sand, Aug 2014, K. Koutroumpa 307 (Z [Z-000278446]), K. Koutroumpa 308 ( B [ B 10 1161812, B 10 1243313], Z [Z-000278441]). — PREFECTURE OF LASITHI: beach of village Vatos, between Myrtos and Tertsa, 34.99686° N, 25.55936° E, rocks and sand, steep, Aug 2014, K. Koutroumpa 299 ( UPA), K. Koutroumpa 301 ( ATH); Vatos, 34.99675° N, 25.55969° E, habitat with Tamarix , Poaceae , Pancratium maritimum and Pistacia lentiscus , on sand-marls, on a ‘carpet’ of dried Posidonia, Aug 2014 , K. Koutroumpa 754 (Z [Z-000278445]), K. Koutroumpa 755 (Z [Z-000278442, Z-000278443, Z-000278444]).

Figures

Fig. 4. Leaf shapes of the three closely related Limonium species in SE Crete – A: L. artelariae (K. Koutroumpa 299, UPA); B: L. cornarianum (K. Koutroumpa 751, Z [Z-000278454]); C: L. hierapetrae (K. Koutroumpa 269, Z [Z-000278465]). – Scale bar = 10 mm.

Fig. 1. Distribution map of the closely related studied Limonium species in E Crete: L. artelariae, L. cornarianum and L. hierapetrae.