Causonis australasica L.M.Lu & Jackes

Trias-Blasi, Anna, Dee, R., Jimbo, Tiberius, Jackes, Betsy & Parmar, Gaurav, 2022, Taxonomic revision of Causonis (Vitaceae) in New Guinea, Edinburgh Journal of Botany 79 (1895), pp. 1-10 : 3-5

1. Causonis australasica L.M.Lu & Jackes , Taxon 70(6): 1203 (2021). – Type: Australia,

Queensland, State Forest Reserve 755, Barong logging area, 17°31′S, 145°50′E, 80 m,

13 vii 1977, Gray 620 (holotype CNS [barcode QRS009328 !]; isotypes BRI [barcode BRI-AQ0542035 !], CANB [barcode CANB514891 !], CNS [barcode QRS009327 !], JCT [barcode JCT-S4021 !]). Image in Parmar et al. (2021: figure 7) .

Herbaceous climber. Stem terete, with longitudinal ridges, branched, often reddish when young, hairs mainly at nodes; tendrils 2- or 3-furcate, without adhesive discs at tips.

Leaves compound, pedately 5-foliolate, alternate, stipules triangular, 2–3(–5) × 1–1.5 mm, caducous; petiole 2.6–9.2 cm, central petiolule 1.1–3.5 cm long, lateral petiolules

0.3–1.8 cm long; central leaflet broadly lanceolate-ovate, elliptic, 5.2–11 × 2.6–5.7 cm,

base rounded or cuneate, upper laterals lanceolate-ovate, elliptic, 2.9–10.8 × 1.9–4.8 cm, base asymmetrical or cuneate; lower laterals lanceolate-ovate, elliptic, 1.7–8 × 0.8–4.2 cm, base asymmetrical or cuneate; apex acuminate, caudate or cuspidate, margin serrate with 5–11 teeth one each side, sometimes sharply serrate, lateral veins 5–9 pairs, pubescent on both surfaces with uniseriate hairs mainly restricted to the veins at maturity, veins inconspicuously raised. Inflorescence a compound dichasium; mostly dividing dichotomously, axillary, leaf-opposed or pseudoaxillary, 3 primary branches, 5–14 × 1–5 cm; peduncle 3–11 cm long. Calyx cupuliform, papillose, shortly lobed. Petals 1.5–2 mm

long, papillose, greenish white to yellowish, apex not corniculate. Stamens 4, filaments 0.5–0.75 mm long, anthers c. 0.5 mm long, oval. Ovary, lower part adnate to floral disc. Floral disc thick, lime green at anthesis. Fruit a berry, globose to oblate, 7–10 mm in diameter, purplish blue to black when mature. Seeds 2–4, triangular in dorsiventral view, c.3.5–5

× 3–4 mm; beak inconspicuous or extending c.1/5 of seed length, apex retuse, chalaza extending c.1/2 of seed length, ventral infolds with two shallow keel-shaped cavities, endosperm nearly T-shaped in cross-section.

Distribution. Australia (Queensland) and Papua New Guinea.

Distribution in New Guinea. Papua New Guinea: Central, East Sepik, Manus, Morobe, New Ireland, Sandaun, Western, and West New Britain ( Figure 1 ).

Habitat and ecology. Forests, hills, from sea level to 1000 m.

Phenology. Flowering and fruiting throughout the year.

Proposed IUCN conservation category. Causonis australasica occurs only in Australia and Papua New Guinea. The EOO and AOO are calculated as 1,095,884 km 2 and 144 km 2, respectively. The EOO suggests that this species might be Least Concern, whereas the AOO suggests it might be Endangered. However, the species does not fulfil the other parameters required for the species to be assessed as Endangered (e.g. small number of locations, continued decline and extreme fluctuations), and therefore this species is classified as Least Concern (LC).

In New Guinea, the EOO is 529,883 km 2 and the AOO is 76 km 2. Similarly to the global conservation assessment, the EOO and AOO indicate a Least Concern and Endangered classification, respectively. However, again the additional parameters necessary for the species to be classified as Endangered are not met, and therefore Causonis australasica is classified as Least Concern (LC) in New Guinea.

Additional specimens examined. PAPUA NEW GUINEA. Central province: Port Moresby subdistrict,

Owens corner, c. 2 miles from Owens Corner–Kokoda Trail due east, 9°25′12′′S, 147°30′00′′E, 24 v 1977, Benjamin and Wiakabu 67848 ( K [ K000871665 ], L [ L.2335866]) ; Port Moresby subdistrict, near Boridi village, 9°5′S, 147°38′E, 2 x 1973, Foreman and Vina LAE60291 ( K [ K000871664 ], L [ L.2335874]). East Sepik province: Hunstein Range, near site ‘Gipa’, along the main stream course, 4°28′S, 142°43′E ,

15 vii 1990, Takeuchi WT6115 ( K [ K000871631 ], L [ L.4253880]) ; Ambunti, Mt Townsend, 4°11′57′′S, 142°48′43′′E, 17 ix 1990, Takeuchi 6950 ( BO [BO-1943768], K, L [ L.4254789]). Manus province: Manus Island, near Kari Village , c. 5 km inland from N. coast in Mundrau limestone depression, 2°2′S, 147°1′E, 19 xi 1975, Sands, Pattison and Wood 2698 ( K [ K000871673 ]). Morobe province: Finschafen subdistrict, Near Arigenang Village , 6°28′, 147°21′, 14 ii 1970, Foreman NGF48104 ( K [ K000871634 ]) ; Bulolo , 7°15′00′′S, 146°42′36′′E, 9 ii 1950, Fryar NGF3987 ( K [ K000871671 ], L [ L.2335870]) ; Oomsis logging area, 6°35′S, 146°25′E, 23 x 1959, Henty NGF11580 ( K [ K000871668 , K000871670 ], L [ L.2329293]) ; Busu river , 6°40′S, 147°E, 14 i 1964, Henty NGF16740 ( K [ K000871635 , K000871632 ], L [ L.2329292]) ; Tuamini river, Lae–Wau road, 6°50′S, 146°35′E, 14 viii 1962, Millar NGF14608 ( K [ K000871639 ], L [ L.2329298]) ; flood plain of Markham River , <20 m, 6°40′59′′S, 146°53′30′′E, 11 iii 1993, Takeuchi 8849 ( BISH n.v., L [ L.4254214], LAE n.v., NSW n.v.) ; Lae, near Taraka Village , 6°37′S, 146°55′E, 9 xi 2012 ,

Wen and Applehans 12300 ( US). New Britain province: West Nakai, Galilo village, near cape Hoskins , 5°28′32′′S, 150°32′57′′E, 27 viii 1954, Floyd 3472 ( K [ K000871676 ]) ; Hoskins subdistrict, Tabai Rekau, 5°25′S, 150°30′E, 19 x 1968, Millar NGF40586 ( K [ K000871667 ], L [ L.2329287]). New Ireland province: West of Kaut plantation, 2°45′S, 150°55′E, 16 ii 1967, Coode and Katik NGF29861 ( K [ K000871638 ],

L [ L.2335872]). Sandaun province: Telefomin, Hak river , 4°53′38′′S, 141°37′08′′E, 5 ii 1981, Morren

210 ( K [ K000871637 ]). West New Britain province: Hoskins subdistrict, on the road to Dagi , 5°31′S, 150°55′E, 21 xii 1967, Coode and Lake NGF32637 ( K [ K000871666 ], L [ L.2335873]). Western province: Kiunga subdistrict, 6°7′S, 141°17′E, 21 vii 1967, Ridsdale and Galore NGF33443 ( BO, K [ K000871674 ], L [ L.2335868]) ; Kiunga subdistrict, 5 miles N. W. of Kiunga, Rumginae Rd. , 6°10′S, 141°20′E, 12 vii 1971, Streimann and Katik 51855 ( BO, K [ K000871660 ], L [ L.2329290]) .

Figures

Figure 1. Map showing the distribution of Causonis australasica, C. maritima and C. trifolia in New Guinea.