Cyrtosperma hambalii (Araceae)
Rhizomatous herb to ca. 1 m tall. Stem condensed, subterranean. Leaves ca. 4 bunched together; petiole erect, short, about half the length of the blade, ca. 17 cm long, geniculate in the apical 1 cm, unarmed, basally dark olive brown, apically mid green, olive green mottled olive brown in between, sheathing in the lower 1/3; blade sagittate, held with the posterior lobes erect and the anterior lobe pointing obliquely down, ca. 32 cm long; anterior lobe much shorter than the posterior, narrowly triangular, 8 cm long, ca. 2.5 cm wide at confluence with posterior lobes; posterior lobes rather narrowly elliptic, ca. 23 cm long, ca. 7 cm wide, apically acuminate for 2 cm; anterior and posterior costae very prominent abaxially, impressed adaxially, the anterior costa without primary venation (i.e. main veins equivalent in thickness to secondary veins of posterior costae) with the main vein running sharply towards the leaf tip; posterior costae naked in the sinus for 5-8 mm, with 5 or 6 primary lateral veins on each side diverging at ca. 30°; secondary and tertiary venation forming a loose reticulum. Inflorescence solitary; peduncle much exceeding the petioles, 47 cm long, armed with scattered (distally increasingly concentrated) straight prickles only in the distal 12 cm. Spathe erect, unarmed, with a prominent central ridge on the abaxial side, very long and slender, 53 cm long, 2.2 cm wide level with the spadix, thence tapering, convolute at the base, distally with the margins close together, dark greenish brown with eight green vertical stripes externally, internally blackish. Spadix much shorter than the spathe, cylindric, blunt, 6 cm long, 0.8 cm thick, sessile; flowers hexamerous, ca. 1.5 mm diam.; anthers exserted from the tepals at male anthesis. Fruit unknown.
This species very closely resembles the rheophytic Cyrtosperma beccarianum in the shape of its leaves, differing in the short petioles. It differs further from that species in the extremely elongate dark greenish brown spathe, hexamerous flowers and exserted stamens. The spathe of C. beccarianum is ovate, wide open and generally white, the flowers are tetramerous and the stamens are not exserted at male anthesis. The very long spathe recalls that of C. cuspidispathum which differs in reaching far larger proportions, having the spathe somewhat reflexed to dangling in the distal part, the stamens not exserted from the tepals at male anthesis, the leaves with well developed anterior lobes and posterior lobes held down, and the petioles with upturned prickles. In the colour of the spathe and in the exserted stamens, C. hambalii recalls C. carrii (Central Province, Papua New Guinea) which differs in its extremely prickly leaves with well developed anterior lobes and in its squat, open spathe. [Hay (1988) noted that the stamens of C. carrii were not exserted at anthesis; this incorrect observation was based on limited herbarium material; subsequent observation of living plants confirms that the stamens are exserted in this species]. Cyrtosperma hambalii is a strikingly elegant plant with its 'rabbit's ears' leaves and slender perfectly erect inflorescence held high above them. The relatively long sheath, reaching a third of the length of the petiole is unusual in the genus, but this may simply be accounted for by the remainder of the petiole being unusually foreshortened.
Endemic to New Guinea; known only from the vicinity Timika in southern West Papua.
Not recorded.