Hanguana sitinurbayai (Hanguanaceae), a new species from mossy montane forest of Gunung Nyiut Penrissen, West Kalimantan, Indonesia Author Randi, Agusti 0000-0002-4262-2604 Natural Kapital Indonesia, Jalan Karna Sosial No. 88, Pontianak, 78121, Indonesia. & Tumbuhan Asli Nusantara Foundation, BTN Korpri Blok C 1 No. 96, Kawatuna, Mantikulore, Palu, 94233, Indonesia. & Integrated Tropical Peat Research Program, NUS Environmental Research Institute (NERI), T-Labs, National University of Singapore, 5 A Engineering Drive 1, Singapore 117411. & randiagusti @ gmail. com; https: // orcid. org / 0000 - 0002 - 4262 - 2604 randiagusti@gmail.com Author Widodo, R. M. Wiwied Balai Konservasi Sumber Daya Alam Kalimantan Barat, Jl. Jenderal Ahmad Yani No. 121, Bansir Darat, Kota Pontianak, Kalimantan Barat 78124, Indonesia. & aryachakti 75 @ gmail. com Author Adirahmanta, Sadtata N. Balai Konservasi Sumber Daya Alam Kalimantan Barat, Jl. Jenderal Ahmad Yani No. 121, Bansir Darat, Kota Pontianak, Kalimantan Barat 78124, Indonesia. & bangsadt 87. sa @ gmail. com text Phytotaxa 2023 2023-07-31 606 3 231 236 http://dx.doi.org/10.11646/phytotaxa.606.3.7 journal article 10.11646/phytotaxa.606.3.7 1179-3163 8202686 Key to Hanguana (Hanguanaceae) in Borneo Adapted from Mohd Fahmi et al . (2012) , and Hroneš et al . (2021) 1. Plants of open habitats (banks of large rivers, margins of freshwater bodies); colonial helophytes with massive, foliaceous stolons; seeds shallowly cupuliform ................................................................................................................................... H. anthelminthica 1. Plants of closed-canopy forests (lowland to montane rainforests, kerangas); clump-forming mesophytes lacking stolons; seeds bowl-shaped or globose with wedge-shaped ostiole .......................................................................................................................... 2 2. Leaf blade corrugated................................................................................................................................................................. H. loi 2. Leaf blade flat..................................................................................................................................................................................... 3 3. Leaf lamina linear-lanceolate to very narrowly elliptic; fruits weakly 3-lobed, ripening medium pink to magenta ......................... 4 3. Leaf lamina elliptic, broadly lanceolate, oblanceolate to elliptic; fruits variable but never 3-lobed, ripening pale yellow, red or black ................................................................................................................................................................................................... 5 4. All parts of the plant (sub)glabrous, without floccose indumentum; sterile bract 1; lowland Kerangas ca. 100 m elev..................... ........................................................................................................................................................................................ H. bakoensis 4. All parts of the plant covered by scattered and densely floccose hairs; sterile bract 2–3; mossy montane forest at 1200–1640 m elev .............................................................................................................................................................................. H. sitinurbayai 5. Small herb, up to 30 cm tall................................................................................................................................................................ 6 5. Medium to large herb, 40–150 cm tall ............................................................................................................................................... 7 6. Stem evenly covered by leaves; lamina elliptic; infructescence deflexed ............................................................................. H. nana 6. Stem apically with terminal crown of leaves; lamina broadly lanceolate; infructescence erect........................................ H. bogneri 7. Leaves 40–70 cm long; infructescence deflexed; ripe fruits red......................................................................................... H. deflexa 7. Leaves 60–100 cm long; infructescence erect; ripe fruits pale yellow or black ................................................................................ 8 8. Lamina oblanceolate to narrowly elliptic, with midrib round-raised abaxially; fruit lageniform, ripening black; stigma terminal, prominently stipitate.............................................................................................................................................................. H. major 8. Lamina elliptic, with midrib weakly impressed; fruit globose, ripening pale yellow; stigma distinctly oblique, sessile.................... ........................................................................................................................................................................................ H. karimatae