Two new species of Ooia (Araceae) from Sabah, Malaysian Borneo

. Two new species of Ooia (Araceae) from Sabah, Malaysia, Ooia sayapensis Kartini and Ooia ulusenagangensis Kartini are described as new species. Both are distinguished from the only current Sabahan species, Ooia kinabaluensis (Bogner) S.Y. Wong & P.C. Boyce by the presence of pistillodes at the pistillate flower zone.


INTRODUCTION
defined Ooia by the spadix axis remaining fresh through to fruit maturation and the spent flowers shedding at the postanthesis.The group is monophyletic (Boyce and Wong 2016), accepting 10 species with the Ooia kinabaluensis (Bogner) S.Y.Wong & P.C.Boyce is the only species recorded from Sabah and Brunei.
The spathes of the genus Ooia S.Y.Wong & P.C.Boyce are remarkably similar in external appearance.However, the spadix at anthesis is critically crucial as the diagnostic characteristics in this genus (Wong and Boyce 2010).Thus, the present presence of about 5-9 spirals of pistillodes at the base of the pistillate flower zone in the two species of Sabahan's Ooia to be described here apparently represents an undescribed taxonomic novelty compared to the very few pistillodes in O. kinabaluensis.
Recognition of these two species, namely O. sayapensis and O. ulusenagangensiss will takes Ooia to three species in Sabah and 12 species on Borneo.and by the pink pistil (versus very few pistilloides and white pistil).Inflorescences smelling of isoamyl acetate (fruity pear odour) at pistillate anthesis is a characteristic shared with O. kinabaluensis.

Etymology
From Sayap + ensis, a suffix denoting the place of origin.

Distribution
Recorded only from Sayap substation, located at the north of the Kinabalu UNESCO Global Geopark in Kota Belud.

Ecology
Rheophytic on shaded Quaternary sandstones, riverine boulders under wet upper hill forest between 900-1100 m above sea level.

Notes
Ooia sayapensis occurs consistently on shaded water-splashed boulders.This medium size rheopyhtic herb have elongated sometimes branched rhizome-like stem and rooting along its length.

Diagnosis
The presence of several rows of pistilloides at the base of pistillate flowers zone is a characteristic shared with O. sayapensis.Ooia ulusenagangensis has a densely arranged glassy white pistil, which is differentiated from O. sayapensis (laxly arranged pink pistil) and O. kinabaluensis (laxly arranged white pistil), as shown in Figure 3.The inflorescences smelling of isoamyl acetate at pistillate anthesis is very weak in O. ulusenagangensis compared to the strong smell in O. kinabaluensis.

Etymology
From Ulu Senagang + ensis, a suffix denoting the place of origin.

Distribution
Recorded only from Ulu Senagang substation, located at the western end of the Crocker Range National Park in Keningau.

Ecology
Rheophytic on exposed Oligocene sandstone, riverine boulders between 400-600 m asl.The surrounding vegetation consists of disturbed hill dipterocarp forest.

Notes
Ooia ulusenagangensis occurs on exposed bare rocks along river of open canopy forest and is frequently exposed to dry conditions at times of low water.A somewhat persistent petiolar ligular about 3 cm long was observed and easily seen in the living collection.