Phyllanthus subg. Macraea (Wight) Jean F.Brunel

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 : 233-235

Phyllanthus subg. Macraea (Wight) Jean F.Brunel

Phyllanthus subg. Macraea (Wight) Jean F. Brunel (1987) 293. — Macraea Wight (1852) 27. — Phyllanthus sect. Macraea (Wight) Baill. (1858) 628; Müll.Arg. (1866) 384; G.L.Webster (1986) 93. — Lectotype (designated by Webster 1986): Macraea oblongifolia Wight (= P. virgatus G.Forst. ).

Erect or prostrate herbs, subshrubs, shrubs or trees, monoecious or dioecious; branching non-phyllanthoid; branches (minutely) ridged or smooth, brown, distally often flattened and/ or winged, often green; (aerial roots occasionally present on nodes in P. womersleyi ). Indumentum absent or short, simple hairs present on (distal parts of the) branches, leaves, petioles, pedicels and ovaries. Stipules triangular, ovate or (sub)orbicular, flat, membranous, translucent chestnut-brown, persistent, base often auriculate. Leaves alternate, distichous, simple, petiolate; blade elliptic, (ob)ovate or (sub)orbicular, margin entire, glabrous, (hairy on both sides in P. tararae and P. wheeleri ); midrib sunken to prominent above, flat or prominent underneath, lateral veins often barely visible, looping and anastomosing near the margin, flat or prominent on both sides. Inflorescences axillary fascicles, unisexual, (rarely) bisexual in some species. Staminate flowers solitary to 12 together, bracteate; pedicel glabrous; sepals 6 (except 5 in P. aoraiensis and sometimes 4 in P. ussuriensis ), elliptic or (ob)ovate, sometimes in two whorls with sepals differing in size and/or shape, imbricate; disc glands alternating with and as many as sepals, circular, flat; stamens 3 (sometimes 2 in P. ussuriensis ), filaments free (connate in P. womersleyi and variably connate in P. prominulatus and P. ridsdalei ), often reflexed, thecae 2, (sub)globular or (sub)ovoid, dehiscencing latrorse via longitudinal slits (pollen: Punt 1980, Wu et al. 2016). Pistillate flowers solitary to 7 together, bracteate; sepals 6, elliptic or (ob)ovate, sometimes in two whorls with sepals differing in size and/or shape, imbricate; disc annular (6 disc glands in P. dumosus , P. tenuipes , P. ussuriensis , P. wheeleri and P. womersleyi , then alternating with sepals), flat; ovary 3-locular (rarely 4-locular in P. lancifolius ), glabrous or pubescent; ovules 2 per locule; style absent to present, stigmas 3, spreading, bifid for between half to 4/5 of the length, reflexed. Fruits capsules, subglobular or oblate, 6-grooved, in some species with 3 grooves deeper than the others and/or bivalved, glabrous or (minutely) verrucate; stigmas and sepals persistent; columella narrowly tetrahedriform, persistent after dehiscense. Seeds trigonous, triangular in transverse section, with convex outer wall, smooth or verrucate, verrucae circular (or rhomboid and stretched widthwise in P. myrtifolius ), sometimes very small, randomly placed or in indistinct longitudinal lines.

Key to the species

1. Stems barely branched, arising from a thick woody rhizome. Staminate disc glands often bell-shaped. — Africa..................................... 9. P. glaucophyllus

1. Stems usually branched several times, growing without a thick rhizome. Staminate disc glands flattened. — Outside Africa........................................ 2

2. Ovary on a gynophore. Stigmas united into a style for 0.3‒0.6 or 1.5‒1.6 mm, then spreading into 3 separate lobes, latter complete bifid or with bifid tips.................... 3

2. Ovary sessile, without gynophore. Stigmas only basally united or entirely free.............................. 4

3. Branches glabrous; internodes 6‒7 mm long. Staminate sepals 1.5‒2 by 0.8‒1 mm; filaments variably connate. Pistillate disc annular. Style 1.5‒1.6 mm high, stigmas 1‒2 mm long with bifid tips................... 16. P. ridsdalei

3. Branches pubescent; internodes 2‒4 mm long. Staminate sepals 1‒1.1 by c. 0.5 mm; filaments free. Pistillate disc consisting of 6 free glands. Style 0.3‒0.6 mm high, stigmas 0.2‒0.5 mm long, completely bifid...... 19. P. tenuipes

4. Leaf margin thickened, flat....................... 5

4. Leaf margin not thickened, flat or revolute........... 7

5. Stipules 0.5–0.7 mm long. Stamens up to 0.4 mm long; filaments sometimes connate. Pistillate pedicel 0.3–1.1 mm long; sepals 0.3‒0.7 by 0.2‒0.5 mm; stigmas 0.2‒0.3 mm long. Fruits 1.5‒1.8 mm diam....... 15. P. prominulatus

5. Stipules 1‒2 mm long. Stamens longer than 0.5 mm; filaments free. Pistillate pedicel 1.5‒10 mm long; sepals 1‒1.5 by 0.5‒1 mm; stigmas c. 1 mm long. Fruits more than 2.2 mm diam..................................... 6

6. Petioles 0.2‒1 mm long; leaf base rounded or obtuse, apex not mucronate, lateral veins 3‒5 on each side of the midrib. Staminate pedicels 1‒1.5 mm long. Pistillate pedicels 1.5‒2.5 mm long. Seeds 1.2‒2 mm long............................................. 2. P. chrysanthus

6. Petioles 1‒1.5 mm long; leaf base oblique, subcordate, apex mucronate, lateral veins 5‒7 on each side of the midrib. Staminate pedicels 2‒4 mm long. Pistillate pedicels 8‒10 mm long. Seeds c. 2.5 mm long..... 9. P. glaucophyllus

7. Branches and/or leaves least partially hairy (check young parts)........................................ 8

7. Branches and leaves completely glabrous.......... 15

8. Pistillate disc consisting of free glands, alternating with sepals....................................... 9

8. Pistillate disc entire, annular..................... 10

9. Internodes 0.8‒1 mm long. Leaf blades 2‒7 by 1.5‒3.5 mm. Stamens c. 0.4 mm long. Ovary glabrous. Fruiting pedicels 8‒12 mm long....................... 5. P. dumosus

9. Internodes 2‒5 mm long. Leaf blades 5‒13.5 by 2‒7 mm. Stamens c. 0.6 mm long. Ovary densely hirsute. Fruiting pedicels 3‒4 mm long................ 23. P. wheeleri

10. Leaf blades densely hairy on both sides, less than 4 mm wide, lateral veins not visible.......... 18. P. tararae

10. Leaf blades glabrous, sometimes distally tomentellous above ( P. samarensis ) or (sparsely) hairy ( P. lancifolius )/ rarely tomentellous ( P. samarensis ) on both sides, wider than 4 mm, lateral veins 6‒11, well visible on each side of the midrib.................................. 11

11. Staminate flowers c. 4 mm diam. Pistillate flower 4‒5 mm diam. Ovary verrucate............... 11. P. macraei

11. Staminate flowers 1‒3 mm diam. Pistillate flower up to 3 mm diam. Ovary hairy, tuberculate or glabrous.... 12

12. Stipule margins fimbriate. Leaf blades obovate, sometimes elliptic, base narrowly cuneate to attenuate. 3. P. clarkei

12. Stipule margins entire. Leaf blades elliptic to oblong or ovate-elliptic, base obtuse, sometimes cuneate, rounded to subcordate............................... 13

13. Leaf blades mostly ovate-elliptic, 9‒79 mm long, apex acuminate.......................... 10. P. lancifolius

13. Leaf blades mostly elliptic to oblong, 7‒38 mm long, apex acute to obtuse or rounded to retuse............. 14

14. Leaf blades 11‒38 mm long; stamens 0.6‒0.8 mm long. Fruiting pedicels 11‒25 mm long........ 6. P. everettii

14. Leaf blades 7‒24 mm long; stamens c. 0.3 mm long. Fruiting pedicels not longer than 11 mm .. 17. P. samarensis

15. Branches strongly winged, wings 0.8‒1 mm wide. Flowers of both sexes with 5 sepals........... 1. P. aoraiensis

15. Branches not winged, ridged or slightly (up to 0.2 mm wide) winged. Flowers of both sexes usually with 6 sepals (but often 4 in the staminate flowers of P. ussuriensis ).... 16

16. Usually prostrate herbs or subshrubs, sometimes erect up to 150 cm high. Stamen filaments connate, but connectives free. Leaf blade irregularly orbicular, 2‒4 mm diam................................... 24. P. womersleyi

16. Usually erect herbs, (sub)shrubs or trees. Stamen filaments free. Leaf blade suborbicular, ovate, oblong, elliptic, obovate, 2‒85 mm long......................... 17

17. Leaf blades obovate, base very narrow, cordate-sagittate................................ 13. P. myrtifolius

17. Leaf blades suborbicular, ovate, elliptic, oblong or sel- dom obovate, base of normal width, cuneate, attenuate, rounded, obtuse or (sub)cordate................. 18

18. Pistillate disc consisting of free glands............ 19

18. Pistillate disc entire, annular.................... 20

19. Leaf blades 2‒7 by 1.5‒3.5 mm, blades only 1.3‒2 times longer than wide; apex retuse to rounded. Staminate flowers with 6 sepals, stamens 3........... 5. P. dumosus

19. Leaf blades 4‒25 by 1.5‒8 mm, blades> 2 times longer than wide; apex obtuse or acute, rarely rounded. Staminate flowers with 4 or 6 sepals, stamens mostly 2, but sometimes 3 on the same plant............... 21. P. ussuriensis

20. Leaf blades 22‒85 by 10‒40 mm, midrib prominent on both sides, lateral veins prominent above. Pistillate pedicels up to 30 mm long.................... 20. P. urceolatus

20. Leaf blades 2‒80 by 1‒32 mm, midrib above flat or sunken (sometimes slightly prominent), prominent underneath, lateral veins flat above or sunken or barely visible. Pistillate pedicels up to 19 mm long..................... 21

21. Staminate flowers 1.5‒4 mm diam. Pistillate flowers 4‒5.5 mm diam................................... 22

21. Staminate flowers 0.7‒1.7 mm diam. Pistillate flowers 1‒3 mm diam................................... 24

22. Leaf blades 3‒37 by 2.5‒18 mm. Staminate flowers 1.5‒ 2.8 mm diam................... 8. P. gardnerianus

22. Leaf blades 7‒80 by 4‒32 mm. Staminate flowers 3‒4 mm diam................................... 23

23. Large shrubs or trees, 0.9–5 m high. Petioles up to 4 mm, leaf blades 7‒80 by 5‒32 mm. Staminate pedicels 1.5‒3 mm long.......................... 4. P. distichus

23. Shrubs to herbs, usually less than 1 m high (exceptionally 2 m in P. pacificus ). Petioles usually shorter than 2 mm, leaf blades 14‒45 by 4‒18 mm. Staminate pedicels 3‒6 mm long........................... 11. P. macraei

24. Staminate pedicels 0.5‒0.8 mm long. Pistillate flowers 1‒1.2 mm diam, pedicels 0.5‒2 mm long........................................... 12. P. minutiflorus

24. Staminate pedicels 0.2‒5 mm long. Pistillate flowers more than 1.5 mm diam, pedicels at least 2.5 mm long.... 25

25. Leaf blades wider than 6 mm, 1.1–3.7 times longer than wide. Staminate sepals 1.2‒1.5 by 1‒1.2 mm; stamens 1‒1.2 mm long..................... 14. P. pacificus

25. Leaf blades at most 6 mm wide; (1‒)2.5‒7.5 times longer than wide. Staminate sepals 0.4‒1 by 0.2‒0.5 mm; stamens 0.3‒0.4 mm long........................ 26

26. Leaf blades 6‒15 by 1‒2 mm. Stipules suborbicular, c. 0.5 by 0.3 mm. Leaf blades small, not longer than 15 mm, usually 5–7.5 times longer than wide, lateral veins barely visible. Staminate flowers c. 0.8 mm diam. Pistillate pedicels 2.5–4 mm long, ovaries always verrucate... 7. P. exilis

26. Leaf blades 3‒40 by 1‒6 mm. Stipules triangular, 1–2.5 by 0.5–1 mm. Leaf blades small to slightly larger, 3–40 mm long, mostly less than 5 times longer than wide (rarely up to 6.7 times), venation prominent, usually 5–8 lateral veins on each side of the midrib. Staminate flowers 0.8‒1.7 mm diam. Pistillate pedicels 3–9 mm long, ovaries glabrous or verrucate.......................... 22. P. virgatus