ARUM GRATUM
PROTOLOGUE: Arum gratum , published in Synopsis Aroidearum: 11 (1856). The protologue is reproduced below.
SYNONYMS:
HOMOTYPIC SYNONYMS: Arum orientale var. gratum (Schott) Engl.
HETEROTYPIC SYNONYMS: Arum melanopus Boiss.
DISTRIBUTION: W. Syria to N. Lebanon: Lebanon, Syria, Türkiye.
SPECIES DESCRIPTION:
Tuberous herb sprouting in early winter from a discoid, vertical tuber 3.4–5 cm across, 1.5–2.5 cm thick. Petiole terete, 17.5–25 (–30) cm long (up to 50 cm long according to Mouterde, 1966), 3–4.5 mm wide, deep green. Leaf-blade hastate-sagittate to oblong-hastate, apex subacute, 9–18 cm long, 7–12 cm wide, deep green, occasionally with jagged purple-black blotches.
INFLORESCENCE:
Inflorescence sweet-smelling. Peduncle very much shorter than the leaves, often absent above soil level, 0–2.5 cm long, 4–5 mm wide, pale green, longitudinally striped with reddish brown. Spathe 12–18.5 cm long; spathe-tube often partially buried, oblong-ventricose, 2–3.5 cm long, 1.5–2 cm wide, constricted apically, exterior off-white below (if buried) or pale green (if exposed), mid-green, stained with purple above, this colour intensifying towards the margins and apex, interior with a pale greenish white lower half and purple upper half; spathe-limb elliptic-ovate, 10–15 cm long, 5–6.5 cm wide, cucullate, acute to minutely acuminate, externally pale green flushed with pale purple, apex and median vein greenish, internally olive-green, ± flushed with pale purple, occasionally with jagged purple-black blotches. Spadix less than ⅓ as long as the spathe-limb, 5.5–6.5 cm in total length; appendix strongly clavate, stipitate, 4–4.5 cm long, 5–6 mm wide, reddish purple to greenish purple, stipe purple. Staminodes in c. 3 whorls forming a zone 1.5–2 mm long; bristles filiform, flexuous, 2.5–3.5 mm long, cream, tipped with purple; bases conic, smooth, cream. Interstices: upper 0.5–1 mm long, smooth, cream; lower ± absent. Staminate flowers in an oblong zone 4–5 mm long, 3.5–4 mm wide; anthers and connectives dull purple. Pistillodes in 1 whorl forming a zone 0.5–1 mm long; bristles aristate, stiff, 1.5–2 mm long, cream, minutely tipped with purple; bases globose, smooth, pale cream. Pistillate flowers in a globose-cylindric cluster 5–7 mm long; ovaries globose, 1.5–2 mm long, cream, barely stained with purple apically; stigma white. Fruiting spike cylindric, 3–4.5 cm long, 2–2.5 cm wide; berries pyriform, 7–10 mm long, 3.5–4.5 mm wide.
ECOLOGY:
Garigue, Cedrus woodland, deciduous woodland; altitude: 550-1500 m
DISTRIBUTION MAPS:
ETYMOLOGY:
Latin gratus, “pleasing, agreeable” — unusually for the genus, the inflorescence is sweet-smelling.
NOTES:
1. Its appendix is strongly clavate and sweetly scented, which sits oddly with its placement in subsection Dischroochiton, diagnosed as foetid or oily-smelling.⁴
2. Its chromosome number has never been established.⁴
3. Peter Boyce described the scent of Arum gratum as that of crushed smoke-bush leaves (Cotinus coggygria), whereas most other members of the Arum orientale complex are foul-smelling.¹²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Arum gratum
2. Synopsis Aroidearum: 11 (1856) — 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. Corazza, G., & L. Cortopassi 2026. Arum brunneoviolaceum (Araceae), a new species from Central Turkey.
10. 2006. Studies on the Genus Arum (Araceae).
11. Gibernau et al 2003. Arum Pollen longevity & viability.
12. Aroid-L mailing list, Peter Boyce, January 5th, 1998
Additional photos by Alan Galloway and Arno Clement, via the International Aroid Society
Additional photo from iNaturalist by ramazanakkaya