genera

Bouman, Roderick W., Kebler, Paul J. A., Telford, Ian R. H., Bruhl, Jeremy J., Strijk, Joeri S., Saunders, Richard M. K., Esser, Hans-Joachim, Falcón-Hidalgo, Banessa & Van, Peter C., 2022, A revised phylogenetic classification of tribe Phyllantheae (Phyllanthaceae), Phytotaxa 540 (1), pp. 1-100 : 10-12

. Keys to the genera based on geographical distribution

The keys below are designed to identify the regional Phyllantheae floras. Some areas have been treated together (i.e., the Americas and the West Indies) as they have many groups in common. For a key to the species of Madagascar, which are markedly different from Africa, it is best to use the key of Ralimanana & Hoffmann (2011), which includes all morphological exceptions to the various (sub)genera. Adjustments need to be considered as some of the subgenera treated for the flora of Madagascar ( Ralimanana & Hoffmann 2011, 2014, Ralimanana et al. 2013, Ralimanana & Cable 2020) are now in separate genera.

The most difficult groups to recognize are the same ones that provide identification issues in their current state. These are the species with a herbaceous or subshrub habit, a character that has evolved several times. This problem is exacerbated by the fact that many of these herbs have become invasive and have become pantropical.

Africa

1. Branching non-phyllanthoid (laminate leaves and flowers on all axes; branchlets not deciduous)...................................................2

1. Branching phyllanthoid (leaves on main stem reduced to scales, the cataphylls; laminate leaves and flowers on lateral axes; lateral branchlets deciduous) or sub-phyllanthoid (leaves at base of branchlets not reduced to scales (often in juveniles); lateral branchlets deciduous)...........................................................................................................................................................................................8

2. Stamens> 10 ................................................................................................................................................................ Lingelsheimia

2. Stamens 2‒7........................................................................................................................................................................................3

3. Pistillode present in staminate flowers .................................................................................................................................. Flueggea

3. Pistillode absent in staminate flowers ................................................................................................................................................4

4. Leaves on all axes spirally arranged...................................................................................................................................................5

4. Leaves on all axes distichous .............................................................................................................................................................6

5. Sepals 5; stamens 5, filaments free.............................................................................................. Kirganelia section Pseudomenarda

5. Sepals 5–6; stamens usually 3 (sometimes 2 or 4), filaments connate…................................................................................. Nellica

6. Sepals 4 in both sexes; staminate disc entire; stamens 4, filaments free; seeds with blue sarcotesta ............................ Margaritaria

6. Sepals 5 or 6 (4 in staminate flowers of C. ussuriensis and C. petraeus , but then 2 stamens in staminate flowers and 6 sepals in pistillate flowers); staminate disc entire or segmented; stamens 2 or 3, filaments free or connate; seeds with no or whitish sarcotesta ............................................................................................................................................................................................7

7. Sepals 4‒6, staminate disc segmented, stamens 2 (but then staminate sepals 4) or 3 .......................................................... Cathetus

7. Sepals 6, staminate disc entire, stamens 2....................................................................................................................... Plagiocladus

8. Stamens 4‒6, filaments free or partly fused (2 free, 3 fused).............................................................................................................9

8. Stamens usually 3, filaments connate...............................................................................................................................................11

9. Herbs or subshrubs, filaments free ........................................................................................................................................ Moeroris

9. Shrubs, sometimes climbing, to small trees, filaments free or fused in two sets .............................................................................10

10. Stamens 2‒5; filaments free; fruits inflated capsules or drupaceous (apple-like) ........................................... Cicca subgenus Cicca

10. Stamens 5; filaments outer 2 free, inner 3 fused in a central column); fruits baccate........................................................ Kirganelia

11. Pistillate inflorescences on proximal position and staminate inflorescences on distal position of plagiotropic branchlets; seeds transversely ribbed—ovary covered with tubercles .......................................................................................... Emblica ( E. urinaria )

11. Pistillate inflorescences on distal position and staminate inflorescences on proximal position of plagiotropic branchlets; seeds longitudinally or transversely striate, but not ribbed............................................................................................................. Moeroris

Asia ( India to Southeast Asia), Australia and Pacific

1. Branching non-phyllanthoid (laminate leaves and flowers on all axes; branchlets not deciduous) or sub-phyllanthoid (leaves at base of branchlets not reduced to scales (often in juveniles); lateral branchlets caducous)...............................................................2

1. Branching phyllanthoid (leaves on main stem reduced to scales, the cataphylls; laminate leaves and flowers on lateral axes; lateral branchlets caducous) ..........................................................................................................................................................................7

2. Disc absent......................................................................................................................................................................... Synostemon

2. Disc present ........................................................................................................................................................................................3

3. Pistillode present in staminate flowers .................................................................................................................................. Flueggea

3. Pistillode absent in staminate flowers ................................................................................................................................................4

4. Leaves on all axes spirally arranged; filaments connate; pistillate disc segmented................................................................. Nellica

4. Leaves on all axes distichous; filaments free or connate; pistillate disc usually entire (when segmented then filaments free, except in Cathetus womerleyi and Cathetus ussuriensis ) ..............................................................................................................................5

5. Sepals 4 in both sexes; staminate disc entire; stamens 4, filaments free; seeds with blue sarcotesta ............................ Margaritaria

5. Sepals 5 or 6 (4 in staminate flowers of Cathetus ussuriensis , but then only 2 stamens in staminate flowers and 6 sepals in pistillate flowers); staminate disc segmented (urceolate in Cathetus gracilis (Hassk.) R.W.Bouman ); stamens 2 or 3, filaments free or connate; seeds with no or whitish sarcotesta......................................................................................................................................6

6. Branchlets not caducous; stipule base mostly auriculate; filaments free or connate, anther connective not enlarged; seeds smooth or longitudinally verrucate .................................................................................................................................................. .. Cathetus

6. Branchlets caducous; stipule base truncate; filaments free, anther connective often enlarged; seeds smooth or transversely striate. .............................................................................................................................................................................................. Lysiandra

7. Disc absent..........................................................................................................................................................................................8

7. Disc present ......................................................................................................................................................................................11

8. Flowers without sepal scales; anthers sometimes apiculate; stigmas usually entire; ovary 3‒15-locular .........................................9

8. Flowers often with sepal scales; anthers not apiculate; stigmas usually bifid; ovary 3-locular.......................................................10

9. Staminate sepals spreading or tubular; filaments free; ovary 3‒5-locular ............................................................ Dendrophyllanthus

9. Staminate sepals often recurved; filaments connate; ovary 3‒15-locular .......................................................................... Glochidion

10. Sepal scales often present in staminate flowers; fruits wider than long; seeds smooth .......................................................... Breynia

10. Sepal scales absent in staminate flowers (except in S. bacciformis ); fruits longer than wide; seeds sculptured ............. Synostemon

11. Herbs or subshrubs ...........................................................................................................................................................................12

11. Shrubs to trees, rarely climbers ........................................................................................................................................................14

12. Pistillate inflorescences on proximal position and staminate inflorescences on distal position on plagiotropic branchlets; seeds transversely ribbed—ovary often covered with tubercles...................................................................................................... Emblica

12. Pistillate inflorescences on distal position and staminate inflorescences on proximal position of plagiotropic branchlets; seeds longitudinally or transversely striate, but not ribbed........................................................................................................................14

13. Cataphyllary stipules (unilaterally) auriculate; filaments connate ........................................................................................ Moeroris

13. Cataphyllary stipules not auriculate; filaments free .......................................................................................................... Phyllanthus

14. Sepals 4 in staminate flowers; stamens 2, filaments connate, anthers dehiscing horizontally (except in Nym. ruber & Nym. touranensis )—pollen pantoporate or clypeate................................................................................................................ Nymphanthus

14. Sepals 5 or 6 in staminate flowers (4 in Cicca acida , but then stamens 4, filaments free); stamens 3–15, filaments free or connate, anthers dehiscing mostly vertically, sometimes horizontally ...........................................................................................................15

15. (Climbing) shrubs; inflorescences axillary or on specialized leafless branchlets; stamens 2 or 5, filaments free or fused in two sets (outer 2 free, inner 3 united), connectives not apiculate; fruits baccate............................................................................. Kirganelia

15. (Climbing, but then stamens 3 and connate) shrubs to trees; inflorescences axillary or on specialized leafless branchlets (then stamens 3 or 4); stamen 3‒20 (when 5 then inflorescences axillary, fruits capsules), filaments free or connate, but not in sets, connectives sometimes apiculate; fruits capsules or drupaceous (baccate in Cicca pinnata and C. orientalis , but then stamens 6) .. ..........................................................................................................................................................................................................16

16*. Branchlets pinnatiform; inflorescences axillary or on separate leafless plagiotropic axes; stamens 4 (in C. acida ) or 6 (in C. Pinnata and C. orientalis ), filaments free; fruits baccate (spherical <2 cm in diam. in C. pinnata and C. orientalis ; star-shaped in C. accida ) ................................................................................................................................................................................... Cicca

16*. Branchlets (bi-)pinnatiform; inflorescences axillary or sometimes paniculate; sepals 4‒6; staminate disc segmented, 4‒6 or 3 bilobed segments; stamens mainly 3 or 5, (in some species up to 20), filaments free (when connate then stamens 3, disc of 3 bilobed segments); stigmas entire, rarely bifid; fruits capsules ......................................................................................... Dendrophyllanthus

16*. Branchlets pinnatiform; inflorescences axillary on leafy plagiotropic branches (floriferous branchlets sometimes with smaller leaves); sepals (4)5 or 6; staminate disc of 5 or 6 glands; stamens 3 or 4, filaments connate; stigmas mostly bifid; fruits (inflated) capsules (except in Emblica officinalis , there spherical drupe 2‒3 cm in diam.) ............................................................................17

17. (Climbing) shrubs to trees; floriferous branchlets sometimes with smaller leaves, Glochidion subg. Phyllanthodendron ); stamens 3 or 4, connectives apiculate; pistillate disc segmented, segments linear; fruits (inflated) capsules ................................................... ........................................................................................................ Glochidion (subgenera Phyllanthodendron & Pseudoactephila )

17. Shrubs to trees; all branches with same size of leaves; stamens 3, connectives apiculate or not; pistillate disc entire; fruits capsules (drupaceous in Emblica officinalis )..................................................................................................................................................18

18. Sepals 6; anthers dehiscing vertically, connectives often apiculate; fruits capsules (drupaceous in E. officinalis )............... Emblica

18. Sepals 5 or 6; anthers dehiscing obliquely to horizontally, connectives not apiculate; fruits capsules................................. Moeroris

Americas (North America, Central America, South America) & West Indies

1. Branching non-phyllanthoid (laminate leaves and flowers on all axes; branchlets not deciduous) or sub-phyllanthoid (leaves at base of branchlets not reduced to scales (often in juveniles); lateral branchlets deciduous) .............................................................2

1. Branching phyllanthoid (leaves on main stem reduced to scales, the cataphylls; laminate leaves and flowers on lateral axes; lateral branchlets deciduous) .........................................................................................................................................................................6

2. Pistillode present in staminate flowers ...............................................................................................................................................3

2. Pistillode absent in staminate flowers ................................................................................................................................................4

3. Petals absent; fruits with 2 seeds per locule; pollen exine verruculose................................................................................ Flueggea

3. Petals present; fruits with 1or 2 seeds per locule; pollen exine reticulate........................................................................ Heterosavia

4. Sepals 4 in both sexes; staminate disc entire; stamens 4, filaments free; seeds with blue sarcotesta ....... Margaritaria (Pantropical)

4. Sepals 5 or 6 in both sexes (sometimes 4 in staminate flowers, but then 2 stamens); staminate disc entire (H-shaped with 2 stamens); stamens usually 3, filaments free or connate; seeds with no or whitish sarcotesta............................................................5

5. Leaves on all axes spirally arranged; sepals 4 in staminate flowers, 6 in pistillate flowers; staminate disc entire, H-shaped around filaments; stamens 2, filaments free ............................................................................................................... Moeroris ( M. arenaria )

5. Leaves on all axes distichous or spiral; sepals 5 or 6 in both sexes; staminate disc segmented or entire (but then filaments connate), never H-shaped; stamens 2, 3 or 5 (when 2 then filaments connate), filaments free or connate ...................................... Phyllanthus

6. Herbs or subshrubs .............................................................................................................................................................................7

6. Shrubs to trees, rarely climbers ........................................................................................................................................................12

7. Inflorescences unisexual.....................................................................................................................................................................8

7. Inflorescences bisexual.....................................................................................................................................................................11

8. Pistillate inflorescences on proximal position and staminate inflorescences on distal position of plagiotropic branchlets; seeds transversely ribbed—ovary often covered with tubercles........................................ Emblica urinaria (Pantropical, but origin Asia)

8. Pistillate inflorescences on distal position and staminate inflorescences on proximal position of plagiotropic branchlets; seeds smooth or longitudinally or transversely striate, but not ribbed ........................................................................................................9

9. Cataphyllary stipules not auriculate .................................................................................................................................. Phyllanthus

9. Cataphyllary stipules (unilaterally) auriculate..................................................................................................................................10

10. Inflorescences unisexual or bisexual; filaments connate, anthers free; seeds smooth or longitudinally striate.................... Moeroris

10. Inflorescences usually unisexual; filaments usually free, sometimes connate, anthers free or connate in a synandrium; seeds smooth, striate or verrucate ............................................................................................................................................... Phyllanthus

11. Stamens 2 or 3, filaments entirely or partially connate (free in M. arenaria ), anthers dehiscing oblique to horizontally (vertically in M. arenaria ); pistillate disc entire; pollen 3-colporate, exine reticulate; seeds smooth or longitudinally striate—North America, pantropical invasive............................................................................................................................. Moeroris subgenus Swartziani

11. Stamens 3, filaments free, anthers dehiscing horizontally; pistillate disc segmented; pollen grains brevicolporate and diorate or porate, exine pilate; seeds verruculose —South America ...................................... Phyllanthus subgenus Conami section Apolepsis

12. Inflorescences axillary fascicles on specialized leafless branchlets or cauliflorous; staminate disc absent; stamens 3 or 4, filaments free (3, filaments connate in C. pseudocicca ); ovary 2- or 3-locular; fruits baccate; seeds without sarcotesta…..................... Cicca

12. Inflorescences axillary fascicles, sometimes paniculate; staminate disc present; stamens 2‒15, filaments free or connate; ovary 3‒6-locular; fruits baccate (inflorescences then shortly stalked) or capsules; seeds with or without sarcotesta .............. Phyllanthus