Zygogynum cruminatum Vink

Vink, W., 2016, The Winteraceae of the Old World. VIII. Some Zygogynum species from New Guinea, Blumea 61 (1), pp. 41-50 : 45

5. Zygogynum cruminatum Vink — Fig. 1

Zygogynum cruminatum Vink (1985) 52. — Type: Kairo NGF 44125 (holo L; iso BRI, CANB, K, LAE n.v.).

Small tree 5–15 m high, but dbh said to reach 70 cm. Bark vertically fissured, mid-green; wood straw, hard, heavy. Young branches rather thick, drying black. Leaves at the end of branchlets; petiole 1–2 cm long, shallowly grooved to flat above, rounded below; blade obovate-oblong to oblong, (12–)15–24 by (3.5–) 5–9 cm, (sub)coriaceous, in sicco greenish grey to (brownish) black below; apex obtuse to broadly rounded, base acute; midrib (slightly grooved to) flat above, prominent and sharp below; margins in vivo and in sicco narrowly recurved; secondary nerves at 65–80° with midrib, arcingly joined at some distance from margin, prominulous on either side. On lower leaf surface only stomata white, solitary; oil cells not apparent. Inflorescences with 3–4 partial inflorescences, these 1-flowered; only buds seen, these drying black; pedicels 23–50 mm long. Calyx shallowly or irregularly ruptured, rather thin, granulose. Petals 15–19 in 2–3 series, free. Stamens c. 200–275; thecae apically touching. Carpels 22–52, free, rather slender; stigma as long as carpel apex, sometimes very shortly but not abruptly descending adaxially; ovules 9–10. Fruitlets unknown.

Distribution — PNG, Morobe Province.

Ecology — Ridge forest dominated by Nothofagus or Pandanus at 1600–2200 m altitude. Flowerbuds May to August. Petals stated to be yellowish green or creamy white.

Specimens examined. PAPUA NEW GUINEA, Morobe Prov.,Langimar rd c. 2 km off Aseki-Menyamya rd,Aseki, Kiapranis & Lawong LAE 69143 (L), 1600 m alt.; Wangini village nr Aseki, Streimann & Kairo NGF 2760 1 (L), 2200 m alt.; Head of Baime Ck, Yamap, Wau subdist., Kairo NGF 44125 (BRI, CANB, K, L), 1800 m alt.

Note — I have seen ovules only in a single bud, in other cases they were too young to be counted. Zygogynum clemensiae also has numerous stamens, but fewer carpels and fewer petals, of which the outer ones are basally connate.

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.).