Lasia spinosa (L.) Thwaites

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

Vernacular

ci yu

Habitat

Swamps, riverbanks, ditches, moist places in tropical and subtropical forests, sometimes cultivated along fish ponds and rice fields. Open swampy sites, sometimes forming large stands; occasionally in boggy places in forest undergrowth (but not flowering there?).

Phenology

Fl. Jul–Sep.

General Description

Herbs, 1–2m tall. Stem long creeping and stoloniferous, erect or ascending, ca. 2.5cm in diam., internodes with stout prickles. Petiole 32–125cm, laxly prickly, sometimes almost smooth; pulvinus 15–35mm, aculeate; leaf blade very variable, sagittate-hastate, 35–65 × 20–60cm, simple or divided; anterior lobe entire or pedate to near midrib, acuminate; posterior lobes strongly downwardly directed to subspreading, once or twice bifid with 3 or 4 narrow to rather long acute or acuminate lateral segments; primary lateral veins 2–4, strong, secondary lateral veins thinner, higher order veins very numerous, all venation flush above, abaxially with rather small, straight to slightly curved prickles. Peduncle to 47cm, laxly prickly. Spathe dull orange to black-red outside, dull yellow to rarely dull crimson inside, 18–35cm with caudate part to 28cm, proximally widened, very much shorter, 3–10cm wide. Stipe of spadix obscure; spadix cylindric, 3–5cm, in fruit elongated to 8cm. Tepals oblong, 1.5–3mm, apex triangular hooded, keeled. Filaments ca. 1.5 × 0.8mm; anthers ca. 0.8 × 0.8mm. Ovary ovoid, ca. 1.5mm high. Fruit obpyramidal, ca. 1cm wide, densely warty-aculeate, sides unarmed, when dry irregularly ribbed, apex truncate. Seed ovoid-cordate, 5–7mm. Clump- and colony-forming suffruticose, often stoloniferous herb; stems ortho-tropic to decumbent, to c. 1.5 m tall/long, with distinct prickly green internodes. Leaves several, petioles prickly, drying spongy, not or faintly mottled; blades pinnatifid to hastate, usually armed beneath, membranous to coriaceous. Inflorescence solitary, on a peduncle similar to but usually somewhat shorter than the petioles. Spathe narrowly lanceolate, convolute at base and usually again above the level of the top of the spadix, often long-acuminate and spirally twisted, erect or recurved, caducous, purplish brown to greenish, with annular, not oblique insertion; spadix sessile. Flowers tetramerous. Fruit green, minutely spiny in upper part, or spines wanting. Seed large, campylotropous, ± pyramidal, c. 1 cm diam.; coat thin, brown, hard, with a few appressed spines; endosperm absent mature seed.

Diagnostic

Stem with distinct armed internodes, usually stoloniferous; leaves entire to 1 x divided.

Distribution

From India to New Guinea.