ARUM CONCINNATUM

Species

PROTOLOGUE: Arum concinnatum , published in Icones Aroidearum: t. 39 (1857). The protologue is reproduced below.

SYNONYMS:

HOMOTYPIC SYNONYMS: Arum italicum subsp. concinnatum (Schott) K.Richt.; Arum italicum var. concinnatum (Schott) Engl.

HETEROTYPIC SYNONYMS: Arum byzantinum Schott; Arum italicum f. purpureopetiolum Engl.; Arum italicum f. viridipetiolatum Engl.; Arum italicum subvar. marmoratum (Schott) Engl.; Arum italicum subvar. nickelii (Schott) Engl.; Arum italicum var. marmoratum (Schott) Nyman; Arum italicum var. sieberi Engl.; Arum italicum var. wettsteinii (Hruby) Engl.; Arum marmoratum Schott; Arum nickelii Schott; Arum wettsteinii Hruby

DISTRIBUTION: S. Greece to SW. Türkiye: East Aegean Is., Greece, Kriti, Türkiye.

DISTRIBUTION NOTE: iNaturalist: Attica, South Aegean.

SPECIES DESCRIPTION:

Tuberous herb sprouting in early autumn from a rhizoma-: tous tuber 7-10 (—15) cm long, 1.5—3.5 cm thick. Petiole terete, 20-45 cm long, 5-12 mm wide, dark to mid-green, sometimes flushed with purple basally. Leaf-blade sagittate-hastate to oblong-sagittate, apex subacute to obtuse, 15—55 cm long, 10-32 cm wide, semi-glossy, dark green, lightly to moderately blotched with silver-grey above

INFLORESCENCE:

Inflorescence smelling strongly of stale urine. Peduncle much shorter than the leaves, terete, 5—14 cm long, 7-12 mm wide, pale to mid-green. Spathe 16-29 cm long; spathe-tube oblong-cylindric, 2—5 cm long, 1.5-2.5 cm wide, constricted apically, exterior pale to mid-green, paler basally, usually flushed with purple along the margin, interior pale greenish white below, mid-purple above; spathe-limb lanceolate-elliptic to elliptic, 14.5-24 cm long, 7-15 cm wide, erect, apex acuminate, the tip soon drooping after opening, externally pale to mid-green, flushed with pale purple along the margins, especially towards the apex, internally greenish white with scattered shiny, translucent patches, + flushed with pale purple along the margins and at the apex, rarely the whole spathe pale purple, or entirely pale green. Spadix more than V? as long to just exceeding the spathe-limb, 9—27 cm in total length; appendix massively conic-cylindric to stoutly clavate-cylindric, shortly stipitate, 7-23.5 cm long, 9-15 mm wide, dull ochre-yellow to pale creamy yellow, more rarely pale purplish cream or purple, stipe cream to yellow. Staminodes in 5—7 whorls; bristles filiform, flexuous, 6-7 mm long, pale yellow, stained with purple; bases conic, verrucate, pale yellow. Interstices: upper 1-2 mm long, longitudinally ridged, pale yellow, lower + absent. Staminate flowers in an oblong zone 5—7 mm long, 9-11 mm wide; anthers and connectives pale yellow, stained with purple apically. Pistillodes in c. 2 whorls forming a zone 3-5 mm long; bristles filiform, flexuous, 3-4 mm long, pale yellow below, purple above; bases bulbiform, smooth, pale cream. Pistillate flowers in a cylindric cluster 9-15 mm long; ovaries ovoid-cylindric, 2.5-3 mm pale green; stigma whitish grey. Fruiting spike oblong-pyriform, 6—7 cm long, 2—2.5 cm wide; berries oblongpyriform, 4—14 mm long, 2.5—5 mm wide.

ECOLOGY:

sea-level to 350 m; altitude: 0-350 m

DISTRIBUTION MAPS:

ETYMOLOGY:

Latin concinnatus, “neatly arranged, elegant”.

NOTES:

1. Of the fifteen species examined by scanning electron microscopy it carries the highest number of elongated sterile flowers, 87.4 ± 8.6 in the upper series.¹²

2. It is recorded as pollinated by flies and beetles — Chironomidae, Drosophilidae, Psychodidae, Sciaridae, Sphaeroceridae and Staphylinidae — but its trap does not match that company. Its papillae are longer than in most midge-pollinated species yet shorter than those of Arum maculatum, and its lacunose area is far larger than in the other two fly-and-beetle species measured. On that evidence it is probably midge-pollinated after all, the staphylinids merely scavenging fallen pollen.¹²

REFERENCES:

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

2. Icones Aroidearum: t. 39 (1857) — protologue.

3. iNaturalist: Arum concinnatum

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. Seymour 2010. Scaling of heat production by thermogenic flowers: limits to floral size and maximum rate of respiration. Plant, Cell & Environment.

8. 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.

9. Sayers et al. 2021. Divergence in floral scent and morphology, but not thermogenic traits, associated with pollinator shift in two brood-site-mimicking Typhonium (Araceae) species. Annals of Botany.

10. Barreto et al. 2025. How to turbo charge respiration – thermogenic metabolism in plants. Current Opinion in Plant Biology.

11. Szenteczki et al. 2022. Transcriptomic analysis of deceptively pollinated Arum maculatum (Araceae) reveals association between terpene synthase expression in floral trap chamber and species-specific pollinator attraction. G3 Genes|Genomes|Genetics.