ARUM EUXINUM
PROTOLOGUE: Arum euxinum , published in Notes from the Royal Botanic Garden Edinburgh 41(1): 46 (1983).
Arum euxinum R. Mill, sp. nov. Ab Arum hygrophilo Boiss. lamina foliorum lobis basalibus vix vel paulo tantum evoluta, pedunculo semper quam petiolis longiori, et appendice spadicis non stipitata differt. Type. Turkey A4 Zonguldak: Kel Tepe, 1450m, open meadow, somewhat marshy; apparently typical Arum of Black Sea area, 1 vi 1967, C. Tobey 1873 (holo. E).
SYNONYMS:
HOMOTYPIC SYNONYMS: Arum hygrophilum subsp. euxinum (R.R.Mill) Alpinar
HETEROTYPIC SYNONYMS: Arum hygrophilum var. ponticum Hruby ex Engl.
DISTRIBUTION: N. Türkiye: Türkiye.
SPECIES DESCRIPTION:
Tuberous herb sprouting in autumn from a discoid, vertically orientated tuber, 3—3.5 cm across, 1.5—2 cm thick. Petiole terete, 6—35 cm long, 2.5-4 mm wide, dark green suffused with purple, especially at the base. Leaf-blade oblong-hastate, apex acute to rather obtuse, 5-11 cm long, 2-6 cm wide, dark green.
INFLORESCENCE:
Inflorescence unscented. Peduncle exceeding the leaves, terete, 10.5–45 cm long, 3.5–5.5 mm wide, dark green, longitudinally striped and stained with purple. Spathe 8–14 cm long; spathe-tube ellipsoid-cylindric, 1.5–3 cm long, 1–1.5 cm wide, tapering apically, exterior pale green, stained with purple, especially along the margin and at the base, interior dark purple; spathe-limb ovate-lanceolate, 6.5–11 cm long, 1.5–4 cm wide, cucullate, acute to briefly acuminate, externally pale greenish stained with purple along the margin and at the base, internally greenish white with a broad, purple margin. Spadix subequal to the spathe-limb, 4–7 cm in total length; appendix very slender-cylindric, stalkless, 2.5–4.5 cm long, 2.5–2.2 mm wide; dark purple. Staminodes in c. 4 whorls forming a zone 3–7 cm long; bristles filiform, flexuous, abundant, 2.5–5 mm long, cream with the upper ⅓ violet; bases barely conic, smooth, pale mauve. Interstices: upper 1–2 mm long, smooth, cream; lower 0–0.5 mm long, smooth, cream. Staminate flowers in a ± oblong zone 1.5–4 mm long, 2–3 mm wide; anthers and connectives violet. Pistillodes in 1 whorl forming a zone 0.7–3.7 mm long, sometimes absent; bristles filiform, flexuous, 2–4 mm long, cream, minutely tipped with violet; bases ± absent. Pistillate flowers in a cylindric cluster, 6–10 mm long; ovaries globose, 1.5–2 mm long, cream, with a very faint pale mauve ring around the stigma; stigma white. Fruiting spike cylindric, 3–4.5 (–7) cm long, 1.5–2 (–2.5) cm wide; berries oblong, 5–9 mm long, 2.5–3.5 mm wide.
ECOLOGY:
Open water meadow, between rocks, beneath Juniperus scrub; altitude: 300-1680 m
DISTRIBUTION MAPS:
ETYMOLOGY:
Of the Euxine — Pontus Euxinus, the Black Sea, whose Turkish coast the species is confined to.
NOTES:
1. Pollinated by midges, with Psychodidae and Sphaeroceridae recorded from the chamber.¹²
2. Its papillae are the shortest measured in any species with papillae at all — 17.00 ± 3.43 µm in the upper chamber — yet it has one of the largest lacunose areas in the genus, the combination typical of midge-pollinated Arum.¹²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Arum euxinum
2. Notes from the Royal Botanic Garden Edinburgh 41(1): 46 (1983) — protologue.
4. Boyce, P.C. 1993. The Genus Arum: a Kew Magazine Monograph. Royal Botanic Gardens, Kew.
5. Boyce, P.C. 2006. Arum – a decade of change. Aroideana 29: 132–137.
9. Delpino 1874. Ulteriori osservazioni e considerazioni.
10. 2006. Studies on the Genus Arum (Araceae).
11. Gibernau et al 2003. Arum Pollen longevity & viability.
Additional photos by David Scherberich