Phyllanthus distichus Hook. & Arn.

Verwijs, J. I. M., Bouman, R. W. & Welzen, P. C. van, 2019, A taxonomic revision of Phyllanthus subgenus Macraea (Phyllanthaceae), Blumea 64 (3), pp. 231-252 : 237-238

4. Phyllanthus distichus Hook. & Arn. — Map 4

Phyllanthus distichus Hook. & Arn. (1832) 95; Müll.Arg. (1866) 413; Hook.f. (1887) 304; W.J. Kress et al. (2003) 233. — Diasperus distichus (Hook. & Arn.) Kuntze (1891) 599. — Lectotype (designated here): Beechey's Voyage (Lay & Collie) s.n. (K (K001056963); iso E, K (K001056962), L (L.2252054), USA, Hawai’i, O’ahu.

[ Phyllanthus argentatus Noronha (1790) 22, nom. nud.]

[ Phyllanthus cheremela Roxb. (1814) 104, nom. nud.]

Phyllanthus sandwicensis Müll.Arg.(1863) 31;(1866) 389;Wawra (1875) 149; Sherff (1939) 563. — Diasperus sandwicensis (Müll.Arg.) Kuntze (1891) 600. — Phyllanthus sandwicensis Müll.Arg. var. oblongifolius Müll.Arg. (1863) 31, nom. inval., not autonym; (1866) 389. — Syntypes: C. Gaudichaud­Beaupré s.n. (P), USA, Hawai’i; L.K.A. Chamisso s.n. (LE), USA, Hawai’i.

Phyllanthus sandwicensis Müll.Arg.var. ellipticus Müll.Arg.(1863) 31; (1866) 389. — Phyllanthus distichus Hook.&Arn.var. ellipticus (Müll.Arg.) Govaerts & Radcl. -Sm. (1996) 176. — Syntypes (based on Müller 1866): C. Gaudichaud­Beaupré 290 ( G,G-DC, P), USA, Hawai’i; Chamisso s.n. ( LE); B . Seemann 2284 (BM).

Phyllanthus sandwicensis Müll.Arg.var. parvifolius Müll.Arg.(1863) 32;(1866) 389. — Phyllanthus sandwicensis Müll.Arg. forma parvifolius (Müll.Arg.) Wawra (1875) 149. — Type: C. Gaudichaud­Beaupré 289 (holo G-DC), USA, Hawai’i.

Phyllanthus sandwicensis Müll.Arg.var. radicans Müll.Arg.(1863) 32;(1866) 389. — Type: C. Gaudichaud­Beaupré s.n. (holo G-DC), USA, Hawai’i .

Phyllanthus sandwicensis Müll.Arg.f. grandifolia Wawra (1875) 149. — Type: W. Hillebrand 2340a (holo W), Hawai’i.

Phyllanthus sandwicensis Müll.Arg. f. rufidus Fosberg (1936) 6. — Type: FR Fosberg 12410 (holo BISH ( BISH1009121 ); iso BISH ( BISH1009120 ), CAS), USA, Hawai’i, Lanai, Haalelepaakai .

Phyllanthus sandwicensis Müll.Arg.var. degeneri Sherff (1939) 567. — Phyllanthus distichus Hook.& Arn.var. degeneri (Sherff) Govaerts & Radcl. -Sm. (1996) 176. — Type: O. Degener 8019 (iso F), USA, Hawai’i.

Shrubs or trees, 90‒500 cm high, monoecious; branches ridg- ed, glabrous,dark or cinnamon-brown,distally flattened, winged, dark brown or sage-green; internodes 3‒10 mm long. Stipules ovate, c. 2 by 1 mm, base cordate, margin erose, spinose or very irregular, apex acute. Leaves: petiole 0.5‒4 mm long, glabrous; blade elliptic, 7‒80 by 5‒32 mm, 1.3‒3.1 times longer than wide, glabrous, upper surface sage-green, sometimes reddish, underneath slightly paler, base rounded, margin not thickened, flat, apex acute, less often obtuse or rounded; midrib flat or sunken above, prominent underneath, lateral veins 5‒11 on each side, flat or sunken on both sides, sage-green above, chestnut-brown underneath. Staminate flowers solitary to 7 together, c. 3 mm diam; pedicel 1.5‒3 mm long, glabrous; sepals 6, elliptic, c. 1.2 by 0.6 mm, light red with pale yellow margin or entirely pale yellow, apex acute; disc glands 6, circular,c. 0.5 mm diam, flat; stamens 3, c. 1 mm long, filaments free, reflexed, thecae subglobular, c. 0.3 mm long. Pistillate flowers in pairs or solitary, c. 5 mm diam; pedicel 8‒10 mm long, glabrous; sepals 6, elliptic, 2‒2.5 by c. 1 mm, light red with pale yellow margin or entirely pale yellow, apex acute; disc annular, with six small lobes alternate to the sepals, crispate, c. 1 mm diam, c. 0.1 mm thick; ovary sessile, globular-oblate, c. 1.5 mm diam, c. 1 mm high, glabrous; style absent, stigmas 3, c. 1 mm long, bifid for half of the length, thin, reflexed. Fruits subglobular, 3‒3.5 mm diam, 6-grooved, glabrous, yellow green; pedicel 8‒12 mm long, glabrous; columella c. 1 mm long. Seeds c. 2 mm high, c. 1 mm wide, smooth, chestnut-brown.

Distribution — Hawai’i (west Maui, O’ahu, Kauai, Molokai and Lanai).

Habitat & Ecology — In dry or rainy forests, thickets and bushland, on rocky ridges, in gulches and on slopes. Altitude: 300‒1000 m. Flowering and fruiting all year round.

Notes — 1. This species is very variable in leaf shape and size. It can be distinguished by its size and robustness of the branches when compared to other species of subg. Macraea .

2. Sherff (1939) distinguished var. degeneri by its distally more alate branchlets and cylindric and more elongate pulvina. None of the distinguishing characters for var. degeneri were found in the material. There is a gradient in leaf size and apex shape that connects var. distichus to var. ellipticus . Both small- and large-leaved specimens were found on the same islands, which further confirms our decision not to distinguish varieties, but to unite them.