Dracontium pittieri Engl.

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

Habitat

It occurs in Tropical moist forest (T-rlf) and Pre-montane moist forest (P-ml) and Tropical wet forest and transition forest to Premontane wet forest life zones (Holdridge et al., 1971). It is often found along river banks, roadsides, secondary growth, and other disturbed areas,

Phenology

Flowering from May to November; one inflorescence was also collected in February; mature fruits in November and February.

Diagnostic

Dracontium pittieri is characterized by having the longest peduncles in the genus. It is easily confused with D. gigas in sterile condition, but differs strikingly in inflorescence morphology (see also discussion of D. gigas). Dracontium gigas has a large spathe and a short peduncle, which is always less than twice as long as the spathe, where-as D. pittieri has a much longer peduncle, 5 to 8 times longer than the spathe. The spathe of D. gigas is more or less hooded at the apex, with the margins broadly overlapping and completely covering the spadix. The spathe of D. pittieri is open at the apex with the margins scarcely overlapping, such that the spadix is exposed. The translucent area at the base of the inner spathe surface extends much higher than the spadix in D. pittieri, while it never exceeds the height of the spadix in D. gigas. Aside from the fact that they are widely separated geographically, D. pittieri could also easily confused with D. peruvianum; they differ, however, in the features of infructescences, seeds, and leaf blades (see discussion of D. peruvianum). A few plants of this species have been brought into cultivation in the United States, but no report of flowering is known. Several plants of D. pittieri are known from John Banta's Nursery (Alva, Florida).

General Description

Tuber hemispherical, 14-20cm diam., 6-8cm thick, flat above, rounded and white to brown below, 20-40cm below ground level; tubercles abundant, irregular-shaped, 0.3-1.5cm long, borne around the periphery of tuber; roots white, to 3mm diam.; cataphylls 3 to 5, 4-40 × 4-7cm, light brown, reaching or surpassing ground level. Leaves solitary; petioles 1.8-4m long above ground, 5-8cm diam. at midpoint, dark green or brownish green, contrastingly mottled with dirty white or pale green blotches and forming a reptilian pattern, smooth or usually with spiny projections; juvenile blade sagittate, or sagittately lobed; mature blade spreading horizontally, 1.2-2m diam., subcoriaceous or thinly coriaceous, rarely fenestrate, never variegated, with abundant raphide cells (some-times), glossy and dark green above, semiglossy and medium green below; middle division 3 or more times trichotomously branched, 80-120 × 50-100cm, with terminal subdivision consisting of 3 sections, with each basal subdivision consisting of many segments; lateral divisions 3 or more times dichotomously branched, 70-120 × 55-90cm, with terminal subdivision consisting of 2 sections, with basal subdivision consisting of many segments; terminal and subterminal sections confluent, each consisting of many segments; leaf segments bilobed or trilobed, broadly oblanceolate, more than 5cm wide on each side of the major ribs, oblanceolate or lanceolate-ovate or triangular, mostly confluent with each other in each division, often with contrastingly smaller rounded or triangular segments alternating with larger segments; apices narrowly acuminate, or caudate; ultimate segments 10-20cm long, confluent with penultimate segments; other segments 10-30cm long; penultimate segments confluent with the subterminal sections; medial segments confluent with the basal subdivisions; basal segments present, confluent with each other; rachises patterned distinct from petiole, pale green, smooth; tertiary veins obscure above, or conspicuous below; bracteoles 3 or 4, 4-40cm long, 5-7cm wide, pinkish, the longest one much shorter than the peduncle, confined at the base. Inflorescence solitary, appearing before new leaf; peduncle 150-250cm long above ground, 4-6cm diam. at midpoint, more than half as long as the petiole, mottled similar to petiole but deeper in color, dark green, smooth or with irregular protuberances; spathe 30-50(70)cm long, 8-12cm wide, cymbiform, non-cucullate, erect or slightly arching, apex obtuse; inner surface semiglossy, maroon or olive-brown or red-purple, with translucent area obvious, (5)10-17cm high, 1.5 to 3 times longer than spadix; outer surface maroon, matte; margins entire, hardly overlapping at the base; veins obscure inside or raised outside, similar to the spathe in color; spadix exposed, sessile, cylindric, brown-purple (tinged green) or purple, 4-9  1- 1.5cm at anthesis, never with appendages at apex. Flower tepals (4)5 or 6(9), 3-4mm long, 1-1.5mm wide, brownish purple or dark purple; stamens 12 to 15; filaments 2-3mm long; anthers 1mm long, slightly exserted; ovary bilocular, whitish; stigma (2)3(4)-lobed; style 3-4mm long above tepals, purple, persistent. Infructescence with spadix 10-20cm long, 3-4cm diam. in fruit; berries 2-seeded, 0.6- 1.2cm diam., 0.9-1.3cm long, subglobose, 3- to 6-angular, apically truncate; young berries medium green; mature berries orange, with abundant raphide cells; seeds 0.9-1.1cm diam., reniform or triangular, light brown, laterally flattened; dorsal ridges obvious, 1, continuous, more than 1mm thick, 0.5-1mm high, warty along both sides, appearing as strongly reduced lateral ridges.

Distribution

Dracontium pittieri is endemic to the Pacific slope in Puntarenas province and adjacent San Jose Province in Costa Rica.