Arum hygrophilum Boiss.

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Phenology

Flowering February to May.

Habitat

Stream sides, ditches, wet flushes, damp soil pockets at rock bases.

Diagnostic

Inflorescence borne beneath the leaves. Spathe-limb internally pale greenish-white with a narrow purple margin. Spadix appendix ? as long as the spathe-limb, slender cylindric, with no stipe, purple. (similar to Arum euxinum)

General Description

Tuberous herb sprouting in early autumn from a discoid vertically (rarely horizontally) orientated tuber 3-6 cm across, 1.5-2.5 cm thick. Petiole terete, 9-75 cm long, 3-6 mm wide, bright mid-green, occasionally with purple staining along the sheath margin and at the petiole base. Leaf- blade lanceolate-hastate, apex acute to subacute, 8-45 cm long, 5-14 cm wide, dark to bright mid-green. INFLORESCENCE unscented. Peduncle shorter than the leaves, terete, 15-45 cm long, 1.5-4 mm thick, bright mid-green. Spathe 7-14 cm long; spathe-tube ellipsoid, 2.5-3.8 cm long, 1.2-2.5 cm wide, waisted above, exterior pale to mid-green, occasionally with purple staining at the base and along the margin, rarely with the entire spathe-tube stained purple, interior deep purple, often with pale greenish white blotches on the rear wall near the base; spathe-limb oblong-lanceolate to elliptic-lanceolate, 5-11.5 cm long, 3-3.5 cm wide, erect to slightly cucullate, acuminate, externally pale to mid-green, purple-flushed along the margin, internally pale greenish-white with a purple margin 0.5-1.5 mm wide.Spadix ? as long as the spathe-limb, 7.5-9.5 cm in total length; appendix slender-cylindric, without a stipe , 5-7.5 cm long, 1.5-3 mm wide, deep purple, occasionally blotched apically with paler purple. Staminodes in 2 or 3 whorls, forming a zone 2-3.5 mm long; bristles filiform, flexuous, 4-5 mm long, pale cream, ± purple at the tip; bases conic, verrucate, cream, stained with purple. Interstices : upper 0-2 mm long, longitudinally ridged, cream; lower ± absent. Staminate flowers in a roughly quadratic zone 4-7 mm long, 5-6 mm wide; anthers and connectives reddish purple. Pistillodes in 2 or 3 whorls forming a zone 2-3 mm long; bristles filiform, flexuous, cream, stained with purple; bases bulbiform, minutely verrucate, cream, speckled with purple. Pistillate flowers a cylindric cluster 4-10 mm long; ovaries oblong-fusiform, pale lime green with a faint purple ring around the stigma; stigma white. Fruiting spike oblong-cylindric, 4-6 cm long, 2-2.5 cm wide; berries angular-pyriform, 4-11 mm long, 3-5 mm wide. Germination epigeal.

Distribution

Morocco, Cyprus, Syria, Lebanon, Israel, Jordan.