Hydnophytum lauterbachii Valeton

9. Hydnophytum lauterbachii Valeton View in CoL — Fig. 10 View Fig ; Map 2 View Map 2

Hydnophytum lauterbachii Valeton (1911) 505. — Type: Versteeg 1226 (lectotype selected here L; iso BO, K), New Guinea, Papua Province , S5°00' E138°30' Noordrivier (= Lorentz river), Sept. 1907 GoogleMaps .

Tuber 15 cm or more across; surface smooth. Entrance holes few, conical, to 1 cm across. Spines occasional, scattered, erect, flexible, blunt, to 0.6 cm in length. Cavities few, tuber somewhat fleshy. Stems several, to 50 by 1 cm, sparsely branched; internodes 1.5–9.5 cm, rounded sometimes with prominent ridges. Leaves spreading. Lamina lanceolate, 9 by 3.5 to 17 by 5.5 cm; apex acuminate; base attenuate; thin to fleshy, dull dark green above, green below; midrib prominent below; veins 6–12. Petiole 1–2 cm; stipules minute, papery, caducous. Inflorescence paired, on small mounds to 0.5 cm across. Bracts minute, caducous. Flowers [4] not heterostylous. Calyx entire, to 1.5 mm. Corolla tube 3.5–4 mm, lobes 1.5–3.5 mm; with a broad ring of hairs at mouth of tube. Anthers 1.5 mm, in mouth of corolla tube. Pollen 57–63 µm, brochi 1–1.5 µm; vesicles 15–20 µm. Stigma 2-lobed, above anthers. Fruit to 6 mm, orange. Pyrenes ellipsoid, 5 by 2.5 mm, abaxial surface with a prominent central ridge; apex apiculate; base acute to rounded.

Ecology & Habitat — Unknown, low altitude. Tuber probably ant-inhabited.

Distribution — Indonesia (western New Guinea) and Papua New Guinea.

Conservation status — Vulnerable (VU) under criteria B1ab(iii)+2ab(iii). This taxon is widespread across much of the lowlands of south-central New Guinea (625 km extent) with herbarium collections indicating 5 locations (subpopulations). Other information: georeferenced collections 5, AOO 12 500 km 2 (using an auto-value cell width of 50 km), EOO c. 16 000 km 2.

Note — A low altitude species from the southern slopes of the central cordillera of New Guinea. The large, thin, and petiolate leaves and a mound-like inflorescence are characteristic. Differs from H. magnifolium [10] in the larger, apiculate pyrenes which are not 3-lobed at the apex.