Zygogynum staufferianum Vink, 2016

Vink, W., 2016, The Winteraceae of the Old World. VIII. Some Zygogynum species from New Guinea, Blumea 61 (1), pp. 41-50 : 49

15. Zygogynum staufferianum Vink , sp. nov. — Fig. 1

Zygogynum staufferianum Vink. — Type: Van Balgooy 968 (holo L; iso A, BISH, CANB, CHR, K, LAE, NSW, P, US, Z ).

Etymology. Named after Hans Ulrich Stauffer (9 Aug.1929 – 21Aug.1965), see Hürlimann 1966, Van Steenis 1974, Endress 1990.

Tree(let) 5–15 m high. Branchlets rather slender to rather stout, brown to grey to black. Leaves scattered along branchlets; petiole 5 –10 mm long, flat with narrow thin edges above, rounded below, dark brown; blade elliptic to narrowly elliptic, 3.5–14 by 1.5–3.5 cm, thinly coriaceous, flat or – more often – slightly bulging up between the secondary nerves, in sicco grey-green on either side, apex (obtuse to) narrowly rounded, base acute to attenuate; midrib impressed above, prominent below, brown; secondary nerves at (65–)70–80° with midrib, arcingly joined at some distance from margin, distinct to prominulous on either side. On lower leaf surface stomata white, solitary (and in short strings or small clusters), not over secondary nerves; oil cells not apparent. Inflorescences with 4–7 partial inflorescences, these 1–10 cm long, with rather slender axes, 3–20-flowered, flowers inserted on axes 1st or 2nd (or 3rd) order, empty bracts below inflorescences 0–9(–20); pedicels 2–10 mm long, rather slender, also in fruit. Calyx 2–3-lobed, not reflexed, 0.8–2 mm long, thin, smooth. Petals 7–10, free, obovate(-oblong), yellowish to pale green, sometimes tinged with red, 5–9 by 2–4 mm, inner ones somewhat longer and narrower than outer ones, apex (broadly) rounded. Stamens 17–29, 1–2.5 mm long, filaments sometimes inflated; thecae apically touching (or slightly separated); connective not prolonged; pollen in tetrads. Carpels 2–5, free, 2–3 by 1–2 by 1–2.3 mm; stigma 0.4–0.7 times as long as carpel apex, not descending adaxially; ovules 14–24. Fruitlets a rather soft berry, globose, red, up to 11 mm diam, with 2/3– 2 mm cylindrical to conical stipe; fruitwall without brachysclereids; pulpa also between the seeds. Seeds (narrowly) obovoid, straight, 2.7–4.5 by 1.2–2.0 mm; testa low-pusticular to subsmooth, (brownish) black.

Distribution — PNG: Western and Eastern Highlands Provinces.

Ecology — Montane (tall, mossy, ridge-)forest at 2400–2770 m altitude. Flowering and fruiting May–July.

Vernacular names — Benamze (Chimbu lang.), Kup (Hagen: Wankl dial.), Ratoaigeh (Goroka: Goreipa dial.).

Specimens examined. PAPUA NEW GUINEA, Western Highlands Prov., Tomba,S.slope of Mt Hagen Ra., Hoogland & Pullen 6145 (A,BO,CANB,K, L, LAE, US ), 2550 m alt.; Tambul, Womersley NGF 14252 (L, LAE ), 2400 m alt.; Eastern Highlands Prov., Marafunga Mill, W. of Fatima R., Grubb & Edwards 61 (L), 2600 m alt.; Mt Wilhelm, east slopes, Brass 30374 (A, CANB, K, L, US), 2770 m alt.; Brass 30486 (CANB, K, L, US), 2600 m alt.; Mt Wilhelm, Komamemambuno, Van Balgooy 968 (A, BISH, CANB, CHR, K, L, LAE, NSW,P, US, Z ), 2750 m alt.; Keglsugl sawmill, Kairo & Streimann NGF 35774 (A, L); Goroka Subprov., Asaro-Mairifutica divide, 1/ 2 mile S of Daulo camp, Pullen 448 (A, BO, CANB, L, LAE, US ), 2400 m alt.

Notes — In several triads with dimerous terminal flowers the lateral flowers showed trimerous calices and corollas.

This species has a special ‘look’ by the relatively narrow leaves, with the secondary nerves at a wide angle, on the lower leaf side often between slightly sunken areas.

Figures

Fig. 1 Carpels, all with ventral side to the left, and at the same magnification. – a. Zygogynum archboldianum; b. Z. bosavicum; c. Z. clemensiae; d. Z. cruminatum; e. Z. cyclopensis; f. Z. ledermannii; g, g'. Z. longifolium; j. Z. megacarpum; h. Z. montanum; i. Z. oligocarpum; k, k'. Z. polyneurum; l. Z. schramii; m. Z. sororium; n. Z. staufferianum; o. Z. umbellatum (a. Brass 12712; b. LAE 58822; c. Clemens 4596; d. LAE 69143; e. Royen & Sleumer 6396; f. Takeuchi 6212; g. Vink BW 8413; g'. Robbins 2004; j. Burley & Ismail 4618; h. LAE 61131; i. Schlechter 16470; k, k'. Jacobs 9489; l. Vink BW 8458; m. Ledermann 11898; n. Balgooy 968; o. Boden Kloss s.n.).