Hanguana (Hanguanaceae)

Hroneš, Michal, UVÍroVá, Alena, Dančák, Martin, Boyce, Peter C. & Leong-ŠkorničkoVá, Jana, 2025, Hanguana ensifolia and H. flavescens, two new species of Hanguana (Hanguanaceae) from western Sarawak, Borneo, Willdenowia 55 (1), pp. 259-269 : 267-268

Key to Hanguana (Hanguanaceae) in Borneo

Adapted from Hroneš & al. (2021) and Randi & al. (2023).

1. Colonial helophytes with massive, foliaceous stolons; seeds shallowly cupuliform; plants of open habitats (banks of large rivers, margins of freshwater bodies).......................... H. anthelminthica

– Solitary or clump-forming mesophytes lacking stolons; seeds bowl-shaped or globose with wedgeshaped ostiole; plants of closed-canopy forests (lowland to montane rainforests, kerangas).......... 2

2. Leaf blade corrugated.... H. loi Mohd Fahmi & al.

– Leaf blade flat to wavy, not corrugated......... 3

3. Leaf blade ensiform, linear-lanceolate to very narrowly elliptic (width: length ratio to 0.1)....... 4

– Leaf blade broadly lanceolate, oblanceolate to elliptic (width: length ratio more than 0.1)............ 6

4. All parts of plant covered with scattered and densely floccose hairs; leaf blade 4.4–6 cm wide; sterile bracts 2 or 3.................. H. sitinurbayae

– All parts of plant (sub)glabrous, without floccose indumentum; leaf blade 1.5–4.5 cm wide; sterile bracts 1 or 2 .................................... 5

5. Plants more than 1 m tall; infructescence deflexed to prostrate; outer tepals distinctly swollen; fruits globose, ripening dull red............. H. ensifolia

– Plants to 1 m tall; infructescence declinate; outer tepals not swollen; fruits weakly 3-lobed, ripening medium pink to magenta............. H. bakoensis

6. Infructescence (sub)erect; fruits ripening white to yellow or black............................ 7

– Infructescence deflexed; fruits ripening red..... 10

7. Fruit large, c. 2 cm long, ripening black, drying lageniform; stigma terminal, prominently stipitate.................................... H. major

– Fruit smaller, to 1 cm long, ripening white to yellowish white, not drying lageniform; stigma sessile... 8

8. Flowering plants small, to 30 cm tall; leaf blade 5–6 cm wide......... H. bogneri Tillich & E. Sill

– Flowering plants larger, 80–140 cm tall; leaf blade 9–25 cm wide............................. 9

9. Leaf blade 50–60 × 9–12 cm, narrowly elliptic to narrowly elliptic-ovate; stigma slightly sunken, stigmatic lobes apically obtuse; seeds with large, incurved appendage on distal part of rim....... H. flavescens

– Leaf blade 70–100 × 15–25 cm, elliptic; stigma strongly raised, stigmatic lobes apically acute; seeds with small, acute appendage on distal part of rim.............................. H. karimatae

10. Mature plants to 30 cm tall; stem evenly covered by leaves; seeds deeply bowl-shaped with large, incurved appendage positioned on distal part of rim................... H. nana Randi & Škorničk.

– Mature plants 50–150 cm tall; stem with a terminal crown of leaves; seeds deeply excavated, with wedgeshaped ostiole accounting for c. 1/4 of seeds, without any discernible appendage on rim..... H. deflexa