Lycianthes lucens S.Knapp, 2022

Knapp, Sandra, 2022, A revision of Lycianthes (Solanaceae) in Australia, New Guinea, and the Pacific, PhytoKeys 209, pp. 1-134 : 1

9. Lycianthes lucens S.Knapp sp. nov.

Figs 28 , 29

Diagnosis.

Like L. vitiensis , but differing in its shrub rather than tree habit, narrowly elliptic rather than elliptic leaves, its fewer-flowered inflorescences that are strictly axillary rather than many-flowered on an elongate axis, presence of triangular calyx appendages versus lack of appendages, anthers that are strictly poricidal versus anthers dehiscing through elongate slits or the pores lengthening with age, and smaller seeds (3 mm versus 4-5 mm long) that lack a distinct notch.

Type.

Papua New Guinea. New Ireland: Lihir Island [Niolam Island], Mount Tementa, above Palie Mission , Namatanai subprovince, 710 m, 7 Nov 1984, O. Gideon LAE-57196 (holotype: LAE [acc. # 256314]; isotypes: K [K000922490], L [L.2882045]) .

Description.

Shrubs 0.5-1.3 m tall; stems terete, glabrous or with very sparse simple or forked uniseriate papillae or trichomes, these sometimes to 5-celled, less than 0.2 mm long, drying reddish gold, the papillae possible glandular, a single collection with adventitious roots from the stem, these filamentous (Croft et al. LAE-71421); new growth glabrous or sparsely papillate, the papillae with darker (glandular?) terminal cells; bark of older stems white to whitish grey, somewhat wrinkled and ridged from drying. Sympodial units difoliate, the leaves geminate, sometimes appearing unifoliate due to the minor leaves abscising, the leaves of a pair similar in shape but not in size. Leaves simple; blades of major leaves 9-15 cm long, 3-7 cm wide, narrowly elliptic, discolorous, membranous; adaxial surfaces very shiny, glabrous; abaxial surfaces glabrous, paler; principal veins 4-7 pairs, yellowish green beneath (in dry material), the midrib not keeled, the veins arching but not forming distinct inframarginal loops; base acute or sometimes somewhat rounded; margins entire; apex acuminate, rarely acute; petioles 0.5-1.5 cm long, completely glabrous; blades of minor leaves 3-9 cm long, 1-4.5 cm wide, shape, texture and pubescence like that of the majors; base acute or sometimes somewhat rounded; margins entire; apex acuminate, rarely acute; petioles 0.3-0.5 cm long, glabrous. Inflorescences axillary fascicles or 1-4 flowers (most often 2-3 flowers), only a single flower open at a time, completely glabrous; pedicels at anthesis 2.5-4 cm long, markedly lengthening just before anthesis, 0.5-0.75 mm in diameter at the base, 1-2 mm in diameter at the apex, pale green or white, spreading or perhaps nodding, completely glabrous and shiny, articulated at the base; pedicel scars in a tight cluster in the leaf axils. Buds ellipsoid, the corolla ca. halfway exserted from the calyx tube before anthesis, completely included in young buds. Flowers 5-merous, heterostylous and unisexual, specimens with either short-styled flowers or long-styled flowers and fruit, the plants perhaps dioecious, the short-styled flowers marginally smaller than long-styled flowers. Calyx tube 2-4 mm long, shorter in short-styled flowers, 2.5-3.5 mm in diameter, openly cup-shaped, white flushed with purple (fide Sands et al. 1966), with (3)4-5 triangular appendages 1-1.5 mm long, ca. 0.5 mm wide, oriented perpendicular to the calyx tube, these usually of differing lengths in a single flower, emerging 0.5-1 mm from the calyx rim, in very young buds the appendages sometimes papillate. Corolla 1.1-2.4 cm in diameter, short-styled flowers at the smaller size end, white or pale purple, stellate, lobed ca. 3/4 of the way to the base, interpetalar tissue present, the lobes 4-8 mm long, 3-4 mm wide, spreading or slightly cupped, membranous, glabrous on both surfaces, the tips and distal portions of the margins densely papillate. Stamens equal; filament tube minute; free portion of the filaments ca. 1.5 mm long, glabrous; anthers 2.5-3 mm long, ca. 1.5 mm wide, ellipsoid, yellow, poricidal at the tips, the pores distally directed, round and not elongating to slits with age. Ovary conical, glabrous, vestigial in short-styled flowers; style in short-styled flowers vestigial, in long-styled flowers 6-6.5 mm long, straight, glabrous; stigma clavate, the surfaces minutely papillate. Fruit a globose berry, 1.2-1.5 cm in diameter, deep red when ripe, green to orange-red to deep red through development, the pericarp glabrous, thin, shiny, translucent; fruiting pedicels 3-4 cm long, longer in mature fruit, 1-1.5 mm in diameter at the base, 3-3.5 mm in diameter at the apex, not markedly woody, pendent (?), pale green; fruiting calyx a spreading plate beneath the fruit, stiff and perhaps fleshy or woody in live plants, the veins leading to the calyx appendages enlarged and prominent. Seeds 50-100 per berry, ca. 3 mm long, 2.5-3 mm wide, flattened and somewhat round with one straight edge in outline, reddish tan, the margins darker, the surfaces deeply pitted, the testal cells pentagonal in outline. Stone cells absent. Chromosome number not known.

Distribution

(Fig. 30 ). Lycianthes lucens is endemic to the islands east of the main island of New Guinea; it has been collected on New Ireland, Lihir Island and the islands of the Louisiade Archipelago (Rossel and West Misima Islands).

Ecology and habitat.

Lycianthes lucens grows in the shaded understory of montane rainforests, from 700 to 1,350 m elevation.

Common names.

None recorded.

Preliminary conservation assessment

( IUCN 2020). EOO (70,602 km2 - LC); AOO (24 km2 - EN). Lycianthes lucens is known from only four localities on widely separated islands; the large EOO consists mostly of uninhabitable ocean. Gold mining on Lihir island is a significant threat for the forest habitat of this species; I suggest a threat status of Endangered (EN [B1,2a, b(iii,iv)]) for L. lucens .

Discussion.

Lycianthes lucens is a beautiful plant, with large flowers, bright red berries and shiny leaves. The species epithet is derived from the shiny, glabrous leaves. Symon (1985) cited Katik et al. LAE-70928 from Rossel Island as L. belensis (as S. belense ), and other specimens in herbaria have been annotated as that species by him. Lycianthes lucens resembles L. belensis in its shiny leaves and mostly axillary inflorescences with few, large flowers but it differs in its glabrous stems and adaxial leaf venation (versus stem and abaxial veins softly pubescent in L. belensis ) and triangular calyx appendages to 1.5 mm long that are perpendicular to the calyx tube (versus appendages that are either absent or less than 0.75 mm long and not obviously perpendicular to the calyx tube in L. belensis ). The calyx rim in L. belensis is thin, transparent and ruffly (see Fig. 8 ), while that of L. lucens is strictly truncate with distinct teeth and not markedly ruffly (Fig. 28 ). Lycianthes belensis is a plant of high elevations in the central ranges, while L. lucens is a plant of montane forests only found on the islands to the east of New Guinea proper.

Lycianthes multifolia has shiny leaves somewhat similar to those of L. lucens but it has smaller flowers (1.4-1.6 cm in diameter versus ca. 2.4 cm in diameter in L. lucens ) and densely pubescent stems and venation (versus glabrous in L. lucens ). Sympodial units of L. lucens are strictly difoliate, while those of L. multifolia often have more than two leaves at a node.

The only other Lycianthes species found as far east in the New Guinea and Pacific area as L. lucens is L. vitiensis from the island of Bougainville to Samoa. Lycianthes lucens differs from L. vitiensis in habit (shrub versus tree) and inflorescence morphology (axillary fascicles versus with a distinct axis), in addition to the other characters mentioned in the diagnosis.

Like other Lycianthes species in the area, L. lucens appears to be dioecious, with individual specimens bearing either short-styled (staminate) flowers or long-styled (pistillate or bisexual) flowers and fruit.

Specimens examined (paratypes).

Papua New Guinea. Milne Bay: Rossel Island, Mt. Rossel, S. slopes, 700 m, 19 Oct 1956, Brass 28494 (A, L); Mt. Oiatau, West Misima Island, subprov. Misima, 700 m, 23 Mar 1979, Croft LAE-71421 (A, K, L, LAE); Mount Rossel, Rossel Island, subprov. Misima, 780 m, 18 Mar 1979, Katik et al. LAE-70928 (A, E, K, L, LAE), 19 Mar 1979, Katik et al. LAE-70954 (K, L, LAE). New Ireland: Lihir Island [Niolam Island], Mount Tementa, above Palie Mission, Namatanai subprovince, 710 m, 7 Nov 1984, Gideon LAE-57196 (K, LAE, L); Hans Meyer Range, on steep ridge below camp, ca. 8 km (map distance) WNW of Taron on east coast, Namatanai subprov., 1,260 m, 9 Oct 1975, Sands et al. 1966 (K), 1,075 m, 8 Oct 1975, Sands et al. 2073 (K), 1,350 m, 15 Oct 1975, Sands et al. 2230 (K).

Figures

Figure 8. Lycianthes belensis herbarium specimen. Indonesia. Papua: Brass 11223 (isotype of S. belense, BM 000778128). Courtesy of the Trustees of the Natural History Museum, London, reproduced with permission.

Figure 28. Lycianthes lucens S. Knapp A flowering branch B flower bud C flower D flower bud with petals removed to show stamens E fruiting branch F berries G seeds. (A, C, E, G Sands et al. 2230 B Sands et al. 2073). Drawing by Lucy Smith. Scale bars: 4 cm (A, E); 7 mm (B, C); 6 mm (D); 2 cm (F); 2.5 mm (G).

Figure 29. Lycianthes lucens herbarium specimen. Papua New Guinea. New Ireland: Sands et al. 2030 (K 000922448). Courtesy of the Trustees of the Royal Botanic Garden, Kew, reproduced with permission.

Figure 30. Distribution of Lycianthes lucens.