ARUM CYLINDRACEUM

Species

PROTOLOGUE: Arum cylindraceum , published in Florae Siculae Synopsis 2(2): 597 (1844). The protologue is reproduced below.

SYNONYMS:

HOMOTYPIC SYNONYMS: Arum italicum var. cylindraceum (Gasp.) Nyman

DISTRIBUTION: Europe to Cyprus: Austria, Bosnia and Herzegovina, Bulgaria, Corse, Croatia, Cyprus, Czechia, Denmark, Germany, Greece, Hungary, Italy, Kosovo, Kriti, Montenegro, North Macedonia, Poland, Portugal, Romania, Serbia, Sicilia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye, Türkiye-in-Europe.

DISTRIBUTION NOTE: iNaturalist: Borsod-Abaúj-Zemplén, Budapest, Burgenland, Békés, Central Denmark, Community of Madrid, Dolj, Fejér, Győr-Moson-Sopron, Heves, Komárom-Esztergom, Lesser Poland Voivodeship, Lower Austria, Lower Silesian Voivodeship, Mehedinți, Nógrád, Pest, Podkarpackie Voivodeship, Southern Denmark, Vas, Veszprém, Vienna.

SPECIES DESCRIPTION:

Tuberous herb sprouting in early winter from a discoid, vertically orientated tuber 3–5 cm across, 1.5–2 cm thick. Petiole terete, 12–18 (–23) cm long, 3–4 mm wide, dark green to mid-green, the lower ¼ occasionally stained with purple. Leaf-blade sagittate to sagittate-hastate, apex acute to obtuse, 9–13 cm long, 3–7.5 cm wide, mid-green.

INFLORESCENCE:

Inflorescence unscented. Peduncle equal to or exceeding the leaves, terete, 11–18 cm long, 4–5 mm wide, light green to mid-green, the lower ⅓ occasionally stained with purple. Spathe 9–14 cm long; spathe-tube oblong-cylindric, 2–3 cm long, 1.5–1.75 cm wide, moderately constricted apically, exterior pale green, interior with the basal ⅓ very pale greenish white, upper ⅔ purple; spathe-limb elliptic-lanceolate, 7–9 cm long, 3.5–4.5 cm wide, erect, acuminate, externally and internally pale green. Spadix ⅓–⅔ as long as the spathe-limb, 5–8 cm in total length; appendix slender-cylindric, slightly to moderately clavate, long-stipitate, 3–5 cm long, 2.5–4 mm wide, pale chocolate-brown to dull purple, stipe fading to cream basally. Staminodes in 2 or 3 whorls forming a zone 2–4 mm long; bristles filiform, semi-rigid, 5–6 mm long, cream; bases bulbiform, verrucate, dull yellow. Interstices: upper 3–5 mm long, smooth, primrose-yellow; lower 2–3 mm long, lower portion with rudimentary pistillode bases, off-white. Staminate flowers in a cylindric zone 5–6 mm long, 3–4 mm wide; anthers purple and connectives yellow. Pistillodes in 3–5 whorls forming a zone 3–5 mm long; bristles aristate-filiform, semi-rigid, 3–4 mm long, cream; bases elongate-bulbiform, slightly verrucate, pale yellow. Pistillate flowers in an oblong-cylindric cluster 15–20 mm long; ovaries oblong, tapering apically, 2–3 mm long, pale greenish yellow, darker towards the stigma; stigma dirty white. Fruiting spike oblong-cylindric, 4–5 cm long, 1.5–2 cm wide; berries pyriform, 5–9 mm long, 3–5 mm wide.

ECOLOGY:

Deciduous woodland, edges of coniferous woodland, open grassy slopes, pasture, rocky slopes; altitude: 450-1700 m

DISTRIBUTION MAPS:

ETYMOLOGY:

Latin, “cylindrical”, for the slender-cylindric spadix-appendix, which separates it from the clavate appendix of Arum maculatum.

NOTES:

1. Pollinated by midges, with Culicidae and Psychodidae both recorded from the chamber.¹²

2. The name has absorbed two others. Boyce treated Arum alpinum as doubtful in 1993; recollected from its type locality it proved identical with Arum cylindraceum, and Arum lucanum went the same way.⁵

REFERENCES:

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

2. Florae Siculae Synopsis 2(2): 597 (1844) — protologue.

3. iNaturalist: Arum cylindraceum

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. 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.

7. 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.

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

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

10. 2006. Studies on the Genus Arum (Araceae).

11. Delpino 1874. Ulteriori osservazioni e considerazioni.