Homalomena mutans
Medium, evergreen, glabrous, strongly aromatic (juniperus/mango resin) weakly clumping mesophytic herbs to c.50 cm tall. Stem pleionanthic, erect to somewhat ascending, c.2.5 cm thick, internodes to c.2 cm long, matte medium green or matte deep red, adventitious roots plentiful, often penetrating the leaf bases. Leaves about 10 together; petiole terete, erect, 25–30 cm long, medium matte green or matte red, bases clasping; pulvinus obscure, c.2.5 cm long, about two-thirds along petiole length; petiolar sheath c.19–13 cm long, about one-quarter of petiole length, slightly unequal, decurrent at apex, margin erect to somewhat incurved, persistent; blade narrowly triangular-sagittate, 10–26 cm long × 8–13 cm wide, thinly leathery, matte dark green adaxially (fresh) with a few scattered darker glands, drying medium olive-brown, abaxially pale green (fresh), drying medium brown, base shallowly and narrowly, cordate, posterior lobes short, straight, ovato-triangular 1–3 cm long, tip acute, acuminate for c.2 cm thence tubular-apiculate for c.3–5 mm; midrib raised abaxially (fresh and dry), green when fresh, drying reddish brown, adaxially sunken slightly into blade, c.2 mm wide; primary lateral veins seven to nine on each side, diverging at 30°–80° from the midrib, adaxially slightly impressed, almost flush with blade when dry, abaxially slightly raised (fresh and dry), distal-most veins curved slightly towards the apex when near the margin; interprimary veins about half width of the primary lateral veins, alternating irregularly with primaries; secondary venation very obscure, striate; tertiary venation not visible, all veins running into a slightly thickened intramarginal vein. Inflorescences up to seven together in a simple synflorescence, erect and smelling powerfully of anise at anthesis, declinate during fruiting, each subtended by prophyll, to c.14 cm long soon marcescent, peduncle to c.13 cm long × c.3 mm diameter, matte medium green or matte red. Spathe 10–13 cm long, tightly furled before anthesis, at pistillate anthesis lower spathe inflating to become ellipsoid-globose, and spathe limb loosening, then opening wide, at staminate anthesis lower spathe becoming narrower and spathe limb also narrowing; entire spathe white at pistillate anthesis; lower spathe ovoid-ellipsoid, 3–3.5 cm long, constricted at the junction of the spathe limb, the constriction coinciding with junction of the staminate and pistillate flower zones; spathe limb ovato-triangular, c.7–6.5 cm long × c.2.5 cm wide (at pistillate anthesis), apex mucronate to c.4mm long. Spadix sub-equalling the spathe, c.9–9.5 cm long, stipitate; stipe c.3mm long × 2 mm diameter, weakly obconical, glossy pale green; pistillate flower zone c.3 cm long × c.1 cm wide, about one-third length of spadix, fusiform; pistils c.1.5mm × 0.75 mm, densely arranged, globose, bright yellow or bright red, red pistils always associated with plants with red peduncles and petioles; stigma capitate, slightly exceeding the ovary, translucent greyish white, each pistil associated with one interpistillar staminode; interpistillar staminodes clavate with a faint central depression, on a slender stipe c.1 mm diameter, sub-equalling the associated pistil, waxy white; interstice to c.1 cm long × 1 cm wide, contiguous with and equalling diameter of pistillate flower zone, covered with large scattered staminodes, these intergrading to the lowermost fertile flowers of the staminate flower zone; staminate flower zone to c.5 cm long, c.1/3 length of spadix; staminate flowers c.3mm × 3 mm trapezoid, comprising three to five truncate stamens, each overtopped by a large, flat connective. Infructescence declinate, spathe entirely persistent, deep reddish, peduncle matte dark green or matte dark red, with paler longitudinal striae. Fruits and seeds not observed.
By the matte dark green leaves with sparse extrafloral nectaries Homalomena mutans most resembles Homalomena sengkenyang P.C. Boyce, S.Y. Wong & Fasih., from which it may be distinguished by the red or yellow (not green) pistils, and by the persistent or only slightly marginally-marcescent (not entirely marcescent-degrading) petiolar sheathes. From all other species of the Homalomena Hanneae complex H. sengkenyang and H. mutans together are distinguished by the matte medium to dark green leaf blades with sparse extrafloral nectaries.
Homalomena mutans is known only from forest remnants in the environs of Kapit town. Extensive fieldwork in the greater surrounding area as far as Batang Balleh to the east and Pelagus to the north has failed to locate further populations of this species, although one of its associated species, H. ibanorum, commonly occurs throughout this area.
Homalomena mutans forms extensive patches, often intermixed with Homalomena ibanorum S.Y. Wong & P.C. Boyce and an as yet to be described species of the Homalomena Hanneae Complex, on open areas of the floor of humid to per-humid lowland dipterocarp forest over shales at between 50 and 100 m.