ARUM DIOSCORIDIS

Species

PROTOLOGUE: Arum dioscoridis , published in Florae Graecae Prodromus 2: 245 (1816). The protologue is reproduced below.

SYNONYMS:

HOMOTYPIC SYNONYMS: Arum dioscoridis var. smithii Engl.

HETEROTYPIC SYNONYMS: Arum cyprium Schott; Arum dioscoridis f. atropurpureum Hruby; Arum dioscoridis f. confluens Hruby; Arum dioscoridis f. guttatum Engl.; Arum dioscoridis f. punctatum Hruby; Arum dioscoridis f. viridulum Hruby; Arum dioscoridis var. cyprium (Schott) Engl.; Arum dioscoridis var. liepoldtii (Schott) Engl.; Arum dioscoridis var. luschanii R.R.Mill; Arum dioscoridis var. philistaeum (Kotschy ex Schott) Engl.; Arum dioscoridis var. punctatum (Hruby) Engl.; Arum dioscoridis var. spectabile (Schott) Engl.; Arum dioscoridis var. syriacum Engl.; Arum dioscoridis var. viridulum (Hruby) Engl.; Arum eggeri Barbey ex Engl.; Arum liepoldtii Schott; Arum philistaeum Kotschy ex Schott; Arum pumilum Kotschy ex Engl.; Arum spectabile Schott; Arum spectabile var. liepoldtii (Schott) Nyman; Arum syriacum Blume

DISTRIBUTION: E. Aegean Is. to Jordan, Cyprus: Cyprus, East Aegean Is., Israel, Jordan, Lebanon, Palestinian Territories, Syria, Türkiye.

DISTRIBUTION NOTE: iNaturalist: Antalya, Mersin, Muğla.

SPECIES DESCRIPTION:

Tuberous herb sprouting in early autumn from a discoid, vertically orientated tuber, 5–10 cm across, 2.5–3 cm thick. Petiole terete, 13–50 cm long, 4–7 mm wide, mid-green, sometimes longitudinally striped with whitish green, more rarely stained with purple. Leaf-blade oblong-hastate to narrowly sagittate-hastate, apex acute, 13–45 cm long, 9–27 cm wide, mid-green, the main and secondary lateral veins sometimes conspicuously paler.

INFLORESCENCE:

Inflorescence smelling strongly of donkey-dung and carrion, rarely odourless. Peduncle usually much shorter than the leaves, rarely almost equalling the petioles, terete, 3.5–10(–42) cm long, 4–10 mm wide, mid-green, rarely stained with purple. Spathe 11–40 cm long; spathe-tube oblong-cylindric, 3–8 cm long, 2–3.5 cm wide, moderately constricted apically, exterior pale to mid-green, sometimes suffused with purple above and along the margin, interior ± greenish white, the apical portion sometimes stained with purple; spathe-limb lanceolate to lanceolate-elliptic, erect, acute to acuminate, 8–37 cm long, (2–)4–11 cm wide, externally pale to mid-green, occasionally stained with purple, especially towards the margin, internally greenish white to mid-green, variously blotched and stained with deep purple-maroon to black-purple, sometimes ± unspotted (var. syriacum) or ± uniformly purple (var. philistaeum). Spadix ½ as long to just exceeding the spathe-limb, 12–28 cm in total length; appendix stout-cylindric, fusiform cylindric or slender-cylindric, almost lacking a stipe to rather long-stipitate, 6–32 cm long, 3–12 mm wide, sooty purple to maroon-purple, very rarely dull yellow, stipe occasionally paler. Staminodes in 2 or 3 whorls forming a zone 1.5–8 mm long; bristles subulate to subulate-filiform, stiff, 2.5–9 mm long, cream to dull purple; bases bulbiform, verrucate, cream, sometimes stained with purple. Interstices: upper 0–5 mm long, longitudinally ridged, cream to dull yellow; lower 0–3 mm long, divided into ± diamond-shaped areas, cream to dull yellow. Staminate flowers in an oblong zone 2.5–8.5 mm long, 4.5–6 mm wide, anthers cream to cream with purple tips, connectives cream or purple. Pistillodes in (1–)2–5 whorls forming a zone 2.5–10 mm long; bristles subulate to subulate-filiform, stiff, 2–7 mm long, cream, to dull purple; bases compressed-bulbiform, verrucate, cream, sometimes stained with purple. Pistillate flowers in an oblong-cylindric cluster 8–30 mm long; ovaries oblong, somewhat truncate apically, pale green to pale yellow, stained with dark purple around the stigma; stigma pale lilac to dirty white. Fruiting spike stout-cylindric, 4–9 cm long, 2–3 cm wide; berries oblong-pyriform, 5–11 mm long, 4–6 mm wide.

ECOLOGY:

Fallow fields, field margins, earth hillsides, waste places, uncultivated olive groves, often very abundant; altitude: 0-2500 m

DISTRIBUTION MAPS:

ETYMOLOGY:

For Pedanius Dioscorides, the Greek physician and pharmacologist of the first century AD, author of De Materia Medica.

NOTES:

1. Pollinated by flies and beetles — Scarabaeidae, Sphaeroceridae and Staphylinidae.¹²

2. It has among the largest trapping cells in the genus: one centimeter above the spathe constriction the papillae have a basal area of 1411.10 ± 315.05 µm², second only to Arum nigrum, and the papillae themselves run 42.90 ± 6.47 µm long at that level.¹²

3. Peter Boyce observed that plants in cultivation under the name cyprium mostly do not match the plant originally described as Arum cyprium, which had a yellow-green spathe with discrete, very deep purple spots and no staining or flushing of the spathe. He added that scientific names were being used as cultivar tags and misapplied, and suggested that the more distinct and stable color expressions of Arum dioscoridis be recognized as cultivars instead.¹³

4. In July 2010 Tony Avent of Plant Delights Nursery described the nursery’s hybrid of Arum dioscoridis × Arum italicum, of which it had several clones, and gave the best clone the tentative name Arum ‘Diosco Duck’.¹⁴

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Arum dioscoridis

2. Florae Graecae Prodromus 2: 245 (1816) — protologue.

3. iNaturalist: Arum dioscoridis

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.

6. Diaz et al. 2006. The effectiveness of some mechanisms of reproductive isolation in Arum maculatum and A. italicum (Araceae). Botanical Journal of the Linnean Society.

7. Chartier et al. 2013. Geographical variations of odour and pollinators, and test for local adaptation by reciprocal transplant of two European Arum species. Functional Ecology.

8. Albre et al. 2003. Pollination ecology of Arum italicum (Araceae). Botanical Journal of the Linnean Society.

9. Linz et al. 2010. Molecular phylogeny of the genus Arum (Araceae) inferred from multi–locus sequence data and AFLPs. TAXON.

10. Gibernau et al. 2025. Mediterranean island endemic Arum pictum emits isomyocorene as a major component of floral scent. Comptes Rendus. Chimie.

11. Corazza, G., & L. Cortopassi 2026. Arum brunneoviolaceum (Araceae), a new species from Central Turkey.