Alyxia, Banks ex R. Br., 1810

Lannuzel, Guillaume, Munzinger, Jérôme, Vandrot, Hervé & Gâteblé, Gildas, 2024, Alyxia Banks ex R. Br. in New Caledonia: a clarification of several species complexes, nomenclatural notes, and a description of three new species, Phytotaxa 649 (1), pp. 1-43 : 3-4

Key to the New Caledonian species of Alyxia (updated from Middleton, 2002 —criteria values are summarized for each species in the appendix)

1. Branchlets strongly angled; leaves in whorls of 4 or 5 ......................................................................................................................2

- Branchlets terete to strongly angled; leaves opposite or in whorls of 3.............................................................................................3

2. Largest leaves 8.1–16.4 cm long, petiole 1–2 cm long; inflorescences branched several times with> 20 flowers ............................ ......................................................................................................................................... Alyxia leucogyne Van Heurck & Müll.Arg.

- Largest leaves 2.4–2.7 cm long, sessile, inflorescence a reduced and sessile to subsessile dichasial cyme........................................ ............................................................................................................................. Alyxia humboldtensis Lannuzel & Gâteblé , sp.nov.

3. Leaves distinctly mucronate ..............................................................................................................................................................4

- Leaves not distinctly mucronate ........................................................................................................................................................8

4. Branchlets sparsely to densely pubescent; leaves pubescent or glabrous beneath; sparsely pubescent around the outside of the corolla tube .................................................................................................................................... Alyxia mucronata D.J.Middleton

- Branchlets and leaves glabrous; corolla tube glabrous outside ..........................................................................................................5

5. Inflorescences very lax, 4.8–14 cm long; pedicels 2.8–22 mm long; fruit articles somewhat sickle-shaped, 2.4–5.7 cm long.......... .................................................................................................................................................................. Alyxia margaretiae Boiteau

- Inflorescences variable, peduncle null to 3.8 cm long; pedicels 0.8–8.5 mm long; fruit articles ellipsoid or fusiform, 0.7–3.7 cm long.....................................................................................................................................................................................................6

6. Leaf blade chartaceous to subcoriaceous; inflorescence 1–3-flowered; corolla tube 7.7–10.2 mm long, 5.4–8.5 times as long as sepals; fruit articles cylindrical........................................................................................................ Alyxia cylindrocarpa Guillaumin

- Leaf blade subcoriaceous to coriaceous; inflorescence 3–11-flowered; corolla tube 3.2–9 mm long, 2.3–4.5 times as long as sepals; fruit articles ellipsoid .........................................................................................................................................................................7

7. Inflorescence 7–11-flowered; peduncle not strongly flattened; corolla tube 3.2–4.2 mm long, 2.3–2.5 times as long as sepals........ ................................................................................................................................................ Alyxia rubricaulis (Baill.) Guillaumin

- Inflorescence 3-flowered; peduncle strongly flattened; corolla tube 5.8–7 mm long, 4.1–4.5 times as long as sepals....................... .......................................................................................................................................... Alyxia poyaensis (Boiteau) D.J.Middleton

8. Sepals oblong, leafy, apex rounded to obtuse; inflorescences concentrated near branch ends; corolla tube densely puberulent outside; corolla lobes densely puberulent outside; fruit articles globular, black, very fleshy................ Alyxia sarasinii Guillaumin

- Sepals ovate or lanceolate, leafy or not, if leafy then apex acute to acuminate; inflorescence position variable; corolla tube glabrous, puberulent around top of tube or only sparsely puberulent outside, corolla lobes glabrous outside; fruit articles of various shapes. ............................................................................................................................................................................................................9

9. Inflorescence 7–11-flowered; branchlets red ......................................................................... Alyxia rubricaulis (Baill.) Guillaumin

- Inflorescence 1–6(–7)-flowered, if 7-flowered then without red branchlets .................................................................................. 10

10. Flowers mostly solitary, sometimes in small fascicules, leaves almost linear .................................................................................11

-. Flowers in inflorescences of 2 or more, if solitary then not terminal; leaves variable in size and shape ...................................... 12

11. Flowers subterminal or terminal and solitary, corolla tube ca. 8 mm long; leaves 0.5–2.2 by 0.15–0.45 cm .................................... .............................................................................................................................. Alyxia caletioides (Baill.) Guillaumin ex Däniker

- Flowers mostly axillary, sometimes subterminal, solitary or in small fascicule, corolla tube ca. 3 mm long, leaves 0.9–1.3 by 0.15–0.25 cm ............................................................................................................................... Alyxia urceolata Lannuzel , sp.nov.

12. Sepals 3.5–4.2mm long; bracts lanceolate or leafy, 4–11 mm long; leaves thickly coriaceous, margins mostly strongly inrolled..... ............................................................................................................................ Alyxia clusiophylla (Baill.) Guillaumin ex Däniker

- Sepals 0.4–3 mm long; bracts mostly deltoid or ovate, rarely lanceolate or leafy, 0.5–2.5 mm long; leaves variable .................. 13

13. Leaves dark green and dull above, venation obscure beneath, usually also obscure above; fruit with 2–8 articles, densely pubescent ....................................................................................................................... Alyxia podocarpa Van Heurck & Müll.Arg.

- Leaves variable but generally shiny above, venation obscure to distinct beneath, not usually obscure on both surfaces; fruit with 1–6 articles, glabrous to only very sparsely pubescent .................................................................................................................. 14

14. Leaf surfaces strongly discolorous, mostly with obscure venation beneath and often glaucous, corolla tube 5.5–9 mm long; fruit articles generally fusiform, 6.3–23.5 mm long........................................................................................ Alyxia baillonii Guillaumin

- Leaf surfaces generally only slightly discolorous if at all, venation variable, only rarely glaucous but if so then corolla tube less than 5.5 mm long; fruit articles variable ......................................................................................................................................... 15

15. Stamens inserted at 4.3–6.4 mm from corolla base ........................................................................................................................ 16

- Stamens inserted at 1–3.9 mm from corolla base............................................................................................................................ 20

16. Petiole 0.1–0.2 cm long; leaves reaching 1.8–3.9 cm long; inflorescence delicate, peduncle at least 6 mm long, ca. 0.3 mm wide; corolla tube 4.3–7.8 mm long, fruit article elongated, longer than 7–7.5 mm ...................................... Alyxia oppositifolia Boiteau

- Petiole 0.3–1 cm long; leaves reaching 5.3–10 cm long; inflorescence robust, peduncle 2–7 mm long, 1.2–1.5 mm wide; corolla tube 6.5–8 mm ................................................................................................................................................................................. 17

17. Leaf blade 3–5.3 by 0.9–2.4 cm; secondary veins on leaves only weakly visible beneath; inflorescence glabrous; sepals glabrous; corolla lobes ca. 4.3 mm long, corolla tube 1.6 times as long as lobes; ovary pubescent in tuft between carpels, fruit article rounded ca. 5 mm long ..................................................................................................................................... Alyxia veillonii D.J.Middleton

- Leaf blade 1.7–10 by 1–4.5 cm; secondary veins on leaves distinct beneath; fruit article ellipsoids 9–40 mm long .................... 18

18. Inflorescence sparsely to densely puberulent all over; sepals densely puberulent; corolla lobes 2.3–3.5 mm long, tube 6.5–7.2 mm long ................................................................................................................................... Alyxia oubatchensis (Schltr.) Guillaumin

- Inflorescence glabrous, sepals glabrous, corolla lobes ca. 4 mm long, tube ca. 8.5 mm long............................................................. ................................................................................................................................. Alyxia paniensis Lannuzel , nom. nov., stat. nov.

20. Branchlets sparsely to densely puberulent ...................................................................................................................................... 21

- Branchlets glabrous ......................................................................................................................................................................... 25

21. All inflorescences subterminal ................................................................................................................. Alyxia kaalaensis Boiteau

- Most inflorescences on a plant clearly axillary, occasionally also with a pseudoterminal inflorescence ....................................... 22

22. Leaf blade densely pubescent on abaxial face....................................................................................... Alyxia nummularia S.Moore

- Leaf blade glabrous, at least apparently .......................................................................................................................................... 23

23. Leaf blade generally obovate, at least 6 mm wide, thickly coriaceous, often with obscure venation, often glaucous beneath; corolla tube 3.6–5.1 mm long; fruit articles 8–16 mm long................................................... Alyxia glaucophylla Van Heurck & Müll.Arg.

- Leaf blade linear to narrowly oblong, less than 10 mm wide, chartaceous, never glaucous beneath............................................. 24

24. Leaf linear, 10–30 × 1.4–2 mm, both surfaces looking lustrous but with sparse and very short hairs; inflorescence with a primary axis pubescent, null to 1.7 mm long; flowers less than 2 mm long.......................................... Alyxia minimiflora Lannuzel , sp.nov.

- Leaf narrowly oblong, 30–40 x 6–7 mm, glabrous; inflorescence with a primary axis glabrous, 0.5–4 mm; flowers ca. 4 mm long ........................................................................................................................................................ Alyxia pseudoserpentina Boiteau

25. Bracteoles present, corolla bud head ellipsoid ........................................................................................ Alyxia loeseneriana Schltr.

- Bracteoles absent or only on terminal flowers’ pedicel, corolla bud head globular or ovate ......................................................... 26

26. Fruit articles 14–20 by 7–9.5 mm, generally about 2 times as long as wide or more; ovary densely pubescent all over; inflorescence 4–6-flowered, lax................................................................................................................................ Alyxia hurlimannii Guillaumin

- Fruit articles 3.5–14.5 by 3.4–9 mm, mostly less than 2 times as long as wide; ovary pubescence variable; inflorescence 1–5- flowered, variable ........................................................................................................................................................................... 27

27. Leaves lanceolate to obovate, mostly> 10 mm wide...................................................................................................................... 28

- Leaves linear to narrowly oblong, or spathulate, mostly <10 mm wider....................................................................................... 30

28. Fruit article globose, ca. 4 mm long, peduncle about half length of leaf blade ........................ Alyxia torquata (Baill.) Guillaumin

- Fruit articles> 6 mm long, with fleshy pericarp; peduncle length less than ¼ of leaf blade.......................................................... 29

29. Corolla tube <2.8 mm long.— New Caledonia....................................................................... Alyxia celastrinea (Baill.) Guillaumin

- Corolla tube> 2.8 mm long.— Loyalty Islands and sand islets around Grande Terre ........................................................................ .................................................................................................................... Alyxia stellata (J.R.Forst. & G.Forst.) Roem. & Schult.

30. Fruit article ellipsoid, 7–10 x 4.5–6.5 mm, corolla tube> 3 mm long, leaves linear 7–20 times longer than wide ............................ ............................................................................................................................................................ Alyxia dolioliflora Guillaumin

- Fruit article globose, ca. 5 mm long, corolla tube <2mm long ...................................................................................................... 31

31. Leaves oblong to spathulate, always less than 20 mm long, black bark ............................................ Alyxia spathulata Guillaumin

- Leaves linear to oblong,> 20 mm long; bark reddish .................................................................................................................... 32

32. Leaves linear, <4 mm wide, 8–12 times longer than wide, primary inflorescence axis <4 mm ....................................................... ........................................................................................................................................... Alyxia rosmarinifolia (Baill.) Guillaumin

- Leaves oblong,> 7 mm wide, 2–4 times longer than wide, primary inflorescence axis 4–7 mm ......... Alyxia tisserantii Montrouz.