Freycinetia pseudopetiolata A.P.Keim, K.Kartawinata & W.Sujarwo

Keim, A. P., Kartawinata, K., Mustaqim, W. A. & Sujarwo, W., 2022, A new species of Freycinetia Gaudich. (Pandanaceae; Freycinetoideae) with pseudopetioliform leaves from Arfak Mountains, Papua, Indonesia, Blumea 67 (2), pp. 156-158 : 157-158

Freycinetia pseudopetiolata A.P.Keim, K.Kartawinata & W.Sujarwo — Fig. 1 , 2

Etymology. The epithet refers to the possession of a pseudopetioliform leaf that characterises the section in which the species is placed.

Diagnosis — Medium-sized climbing pandan with a conspicuous pseudopetioliform leaf, auricle with spines in the margin, number of stigmatic remains 2–4. — Type: W. A. Mustaqim 1478 (holo BO!), Indonesia, West Papua, Arfak Regency, Angga Gida District , Mount Tombruk , S1°21'54.0" E133°55'53.7" .

Medium-sized climbing pandan; climbing up to 5 m high. Stem greyish green to grey, 0.7–0.8 cm diam, glabrous. Leaf: sheath 8–9 cm long, glabrous; auricle tapered (not lobed), margin with spines; blade lanceolate-elongate, c. 53 by 2.5 cm, subbasally pseudopetiolate for c. 2 cm long, apex acute, leaf margin throughout with spines, surfaces glabrous, green, reddish green in the basal part. Infructescence terminal, ternate or quaternate (with 3 or 4 cephalia per infructescence), 13–14 cm long; peduncle c. 4 cm long; pedicel 3.5–4 cm long, stout, scabrous. Cephalia 3 or 4 per infructescence, elongate ellipsoidal, 6–9 by c. 2.5 cm wide. Berry prismatic; stigmatic remains 2–4.

Distribution — Endemic to the Bird’s Head Peninsula (Arfak Mountains) in the extreme north-western corner of mainland New Guinea.

Habitat & Ecology — Lower mountain forest at mountain ridges at about 2250 m altitude.

Conservation Status — Likely, Critically Endangered ( CR) as F. pseudopetiolata is only known from the type .

Notes — This species can easily be distinguished in the field by the presence of the pseudopetioliform leaf as F. pseudopetiolata is, so far, the only species in mainland New Guinea with this character. Pseudopetioliform is defined here as a narrowing in the basal part of the lamina to the extent that the leaf seemingly has a petiole (hence the origin of the epithet pseudopetiolata ). Because of the rather unique pseudopetiole and irrespective of also having fairly obvious spines in the margin of the auricle, F. pseudopetiolata is regarded here to be better classified in section Pseudopetiolosae than the section Hemsleyella B.C.Stone (see Stone 1968). The differences between F. pseudopetiolata and the other two members of the section Pseudopetiolosae are described in Table 1.

Figures

Fig. 1 Freycinetia pseudopetiolata A.P.Keim, K.Kartawinata & W.Sujarwo from which the holotype (W.A. Mustaqim 1478, BO) is made.a–b. Habit; c. leaf with bright orange colouration in the basal part; c–e. quaternate infructescence. — Scale bars c–e = 1 cm. — Photos: W.A. Mustaqim, 2016.

Fig. 2 Freycinetia pseudopetiolata A.P.Keim, K.Kartawinata & W.Sujarwo, holotype showing the pseudopetioliform leaf and quaternate infructescence. — Photo:A.P. Keim, 2022.