Cuphea, P. Browne, 1756

Facco, Marlon Garlet & Cavalcanti, Taciana Barbosa, 2022, Novelties in Cuphea (Lythraceae) from Serra do Espinhaço and Serra da Mantiqueira, and a key to the species from Minas Gerais state, Brazil, Phytotaxa 568 (3), pp. 267-276 : 272-274

Key to the species of Cuphea from Minas Gerais state, Brazil

1. Floral tubes 13–32 mm long, red, red-orange, red-purple, violet-purple, yellow-green to green or purple in the dorsal region and ventrally green .................................................................................................................................................................................. 2

- Floral tubes 2.5–9 mm long, cream colored, yellow-green, green ventrally and dorsally purple or atroviolaceous, if 10–14 mm, never red ........................................................................................................................................................................................... 9

2. Racemes bracteose, leaves abruptly reduced in size in the inflorescence; flowers concentrated in the apex; petals 0 ................... 3

- Racemes frondose, leaves gradually reduced in size in the inflorescence; flowers distributed along the inflorescence; petals 6 ... 4

3. Plants with malpighiaceous trichomes on the branches, the trichomes bifid with long thin arms; petioles 5–10 mm long; ovules 25–100+ ................................................................................................................................................................. C. melvilla Lindl.

- Plants with erect or curved eglandular trichomes and glandular trichomes on the branches, not malpighiaceous; petioles 0–1 mm long; ovules 3–8 .................................................................................................................................................... C. pulchra Moric.

4. Floral tubes entirely yellow or yellow-green........................................................................... C. lucens T.B.Cavalc. & S.A Graham

- Floral tubes red, red-orange to red-purple with yellow-green apex, or green to yellow-green with bright red apex, or purple in the dorsal region and ventrally green ..................................................................................................................................................... 5

5. Petals persistent in the floral tube in fructification, curling into the tube; floral tube purple in the dorsal region and ventrally green ........................................................................................................................................................... C. fuchsiifolia A.St. -Hil.

- Petals caducous in the floral tube in fructification; floral tube red, red-orange to red-purple with yellow-green apex, or green to yellow-green with bright red apex .................................................................................................................................................... 6

6. Leaf margin crenate with glandular trichomes; floral tubes 13–19 × 2–3 mm; ovules 3 ................................................................. 7

- Leaf margin not crenate, glabrous; floral tubes 19–32 × 4–6 mm; ovules 5–21 .............................................................................. 8

7. Leaves orbicular or broadly elliptic to ovate; floral tubes 13–15 mm long; petals bright red or red with dark purple apex, 4–6 mm long ......................................................................................................................................................... C. rubrovirens T.B.Cavalc.

- Leaves oblong or broadly elliptic; floral tubes 15–19 mm long; petals red-purple, 3–4 mm long ................. C. teleandra Lourteig

8. Leaf base subcordate; floral tube base rounded, scarcely spurred, 0.5–1 mm long; ovary prominently enlarged dorsally (gibbous) ........................................................................................................................................................................... C. hybogyna Koehne

- Leaf base acute; floral tube base distinctly spurred, spur 1–2 mm long, descending; ovary equally enlarged on all sides (nongibbous) ............................................................................................................................................ C. grandiflora Pohl ex Koehne

9. Pedicel without bracteoles .............................................................................................................................................................. 10

- Pedicel bibracteolate ....................................................................................................................................................................... 14

10. Flowers alternate; floral tubes 4–5 mm long; nectariferous gland around the base of the ovary, cupuliform ..................................... ................................................................................................................................................................... C. anagalloidea A.St. -Hil.

- Flowers opposite; floral tubes 6–10 mm long; nectariferous gland at the base of the ovary unilateral, narrowly to broadly ovate .. ......................................................................................................................................................................................................... 11

11. Leaves ovate to elliptic, 8–35 mm wide ......................................................................................................................................... 12

- Leaves oblong, oblong-lanceolate to narrow-oblong, 2–7 mm wide ............................................................................................. 13

12. Leaf base obtuse to acute; dorsal petals not larger than ventral .............................................................. C. racemosa (L.f.) Spreng.

- Leaf base cordate; dorsal petals much larger than ventral ............................................................................... C. schwackei Koehne

13. Subshrubs, robust; petiole 1–2 mm long; style glabrous ................................................................................... C. fruticosa Spreng.

- Herbs, delicate; petiole 3–8 mm long; style villous ....................................................................... C. ramosissima Pohl ex Koehne

14. Leaves linear, rarely narrow-lanceolate, 5–12 times longer than wide .......................................................................................... 15

- Leaves ovate, obovate, oblong, orbicular, lanceolate, elliptic, 1–3 times longer than wide, never linear ..................................... 26

15. Plants with malpighiaceous trichomes on the branches, bi-armed, rarely second arm shorter ...................................................... 16

- Plants with erect or curved, short eglandular trichomes and long glandular trichomes, not malpighiaceous, rarely golden glands present on the branches .................................................................................................................................................................. 19

16. Herbs procumbent; leaves 2–8 mm long; stamens deeply included, filaments free in the median portion of the floral tube ............. ................................................................................................................................................................................. C. repens Koehne

- Subshrubs erect; leaves 10–60 mm long; stamens exserted to subexserted, filaments free in the apical portion of the floral tube ... ......................................................................................................................................................................................................... 17

17. Leaves coriaceous, stiff; seeds 1–3; plants without xylopodium ................................................................... C. sclerophylla Koehne

- Leaves membranous to chartaceous, not stiff; seeds (3–)6–23; plants with xylopodium ............................................................. 18

18. Petiole 1.5–4 mm long; floral tubes 9–14 mm long; seed margin acute, winged ....................................... C. pterosperma Koehne

- Petiole 0–1 mm long; floral tubes 6–8 mm long; seed margin obtuse, thick ............................................ C. retrorsicapilla Koehne

19. Leaves 3–4(–7)-verticillate, at least in the midstem ....................................................................................................................... 20

- Leaves opposite .............................................................................................................................................................................. 24

20. Leaf margin strongly revolute to midvein ................................................................................................ C. sperguloides A.St. -Hil.

- Leaf margin plane or subrevolute, not reaching midvein ............................................................................................................... 21

21. Herbs procumbent; leaves with golden glands; spur of the floral tube inconspicuous; ovules 50–60....... C. arenarioides A.St. -Hil.

- Subshrubs to shrubs erect; leaves without golden glands; spur of the floral tube evident, horizontal to strongly deflexed; ovules 3–6 .................................................................................................................................................................................................. 22

22. Pedicel 7–30 mm long; infrastaminal vesicles present .............................................................................. C. hyssopoides A.St. -Hil.

- Pedicel 2–5 mm long; infrastaminal vesicles absent ...................................................................................................................... 23

23. Brachyblasts present (short branches with very short internodes); petals yellow................................................................................ ........................................................................................................................... C. paralarix (Lourteig) T.B.Cavalc. & S.A.Graham

- Brachyblasts absent; petals purple or pink ........................................................................................ C. ericoides Cham. & Schltdl.

24. Pedicel 7–30 mm long; plants with xylopodium ....................................................................................... C. hyssopoides A.St. -Hil.

- Pedicel 1–5 mm long; plants without xylopodium ......................................................................................................................... 25

25. Leaf margin strongly revolute to midvein; ovules 3; stamens deeply included, filaments free in the middle portion of the floral tube ................................................................................................................................................................. C. tenuissima Koehne

- Leaf margin plane; ovules 4–7(–12); stamens exserted, filaments free in the apical portion of the floral tube .................................. ............................................................................................................................................................ C. thymoides Cham. & Schltdl.

26. Stamens free in the middle third of the floral tube, deeply included (rarely in C. inaequalifolia ); ruderal plants ........................ 27

- Stamens free in the upper third of the floral tube, exserted to subexserted; plants not ruderal ..................................................... 31

27. Floral tube not spurred; racemes bracteose, distinct ...................................................................................................................... 28

- Floral tube spurred, spur acute to obtuse, horizontal to deflexed; usually racemes frondose, indistinct, sometimes bracteose ( C. micrantha ) ...................................................................................................................................................................................... 29

28. Petiole 0–3 mm long; pedicel not forming an angle; seed margin obtuse ....................................... C. calophylla Cham. & Schltdl.

- Petiole 10–25 mm long; pedicel forming an angle of 90°; seed margin acute ....................................... C. circaeoides Sm. ex Sims

29. Ovules 3(–4), seed margin obtuse, without wing ............................................................................................... C. micrantha Kunth

- Ovules 5–9; seed margin acute, with a thin wing ........................................................................................................................... 30

30. Floral tube 6–9 mm long, uniformly strigose, mixed with sparse glandular trichomes; bracteoles apex long-attenuate .................... .............................................................................................................................................................................. C. strigulosa Kunth

- Floral tube 4–6 mm long, glabrous between the veins, with sparse glandular trichomes on the veins; bracteoles apex acute ........... ................................................................................................................................................... C. carthagenensis (Jacq.) J.F.Macbr.

31. Petiole 10–25 mm long; racemes bracteose, distinct ............................................................................. C. impatientifolia A.St. -Hil.

- Petiole 0–7 mm long; racemes frondose, indistinct ........................................................................................................................ 32

32. Floral tubes yellow to yellow-green; petals yellow............................................................................ C. brachiata Mart. ex Koehne

- Floral tubes greenish, beige, rose, purple, atroviolaceous, green ventrally and purple dorsally; petals purple, pink, lilac, rarely white ............................................................................................................................................................................................... 33

33. Floral tube spur acute, upward ........................................................................................................ C. linarioides Cham. & Schltdl.

- Floral tube spur obtuse, horizontal to deflexed .............................................................................................................................. 34

34. Pedicels of mature flowers 0–6 mm long ....................................................................................................................................... 35

- Pedicels of mature flowers 7–30 mm long ..................................................................................................................................... 52

35. Petals persistent in fructification, winding up into the floral tube ................................................................................................ 36

- Petals caducous in fructification ..................................................................................................................................................... 37

36. Leaves 6–12 mm long, petioles 0–3 mm long; petals with trichomes on the central vein .......................... C. sessiliflora A.St. -Hil.

- Leaves 15–22 mm long, petioles 5–9 mm long; petals without trichomes on the central vein ............ C. lutescens Pohl ex Koehne

37. Leaves 0.5–3 mm wide, imbricate or often fasciculate .................................................................................................................. 38

- Leaves 4–30 mm wide, not imbricate or fasciculate ...................................................................................................................... 40

38. Leaves imbricate, appressed to the stem, opposite ...................................................................................... C. diosmifolia A.St. -Hil.

- Leaves not imbricate, often fasciculate, 3-verticillate, if subalternate then plants black when dried ............................................ 39

39. Floral tube 5.5–10 mm long, hispid; ovules 4–7(–12); seed margin acute; plants black when dried .................................................. ............................................................................................................................................................ C. thymoides Cham. & Schltdl.

- Floral tube 5–6 mm long, hirsute; ovules 2–3; seed margin obtuse; plants greenish-brown when dried ......... C. disperma Koehne

40. Leaf blade with secondary and tertiary veins conspicuous in both surfaces .................................................................................. 41

- Leaf blade with secondary and tertiary veins inconspicuous in both surfaces or only the secondary veins visible ...................... 44

41. Abaxial surface of the leaves villous; floral tubes 11–14 mm long ........................................................... C. cipoensis T.B.Cavalc.

- Abaxial surface of the leaves strigose or near glabrous; floral tubes 7–10 mm long ..................................................................... 42

42. Leaves discolorous, adaxial surface shining, 10–30 mm wide; floral tubes brownish to greenish, vinaceous in the dorsal region ... ................................................................................................................................................................................ C. pohlii Lourteig

- Leaves concolorous, opaque, 5–15 mm wide; floral tubes vinaceous in the dorsal region, cream-green or greenish ventrally .....43

43. Leaves orbicular to broadly ovate, strigose, one-armed cystolithic appressed trichomes present; pedicels 1.5–2 mm long .............. ................................................................................................................................................... C. venosa M.G.Facco & T.B.Cavalc.

- Leaves narrowly ovate to ovate-oblong, rarely elliptic, near glabrous, one-armed cystolithic trichomes absent; pedicels 2–6 mm long .................................................................................................................................................... C. pseudovaccinium A.St. -Hil.

44. Leaves near glabrous on both surfaces ........................................................................................................................................... 45

- Leaves strigose, hirsute to pubescent ............................................................................................................................................. 46

45. Floral tubes 7–9 mm long; the 2 dorsalmost short stamens pilose; pistil ca. 3.9 mm long .................... C adenophylla T.B.Cavalc.

- Floral tubes 10–12 mm long; the 2 dorsalmost short stamens glabrous; pistil 9.5–10 mm long ......................................................... ................................................................................................................................................ C. dryadica M.G.Facco & T.B.Cavalc.

46. Floral tube spur strongly deflexed; ovules 3 ................................................................................................................................. 47

- Floral tube spur horizontal to slightly upward; ovules 5–15 (rarely 3 in C. acinos ) ...................................................................... 50

47. Bracts asymmetrical along the raceme, one of the bracts in the pair strongly reduced ............................ C. inaequalifolia Koehne

- Bracts subequal along the raceme .................................................................................................................................................. 48

48. Leaves ovate to ovate-lanceolate, base cordate to subcordate, basal leaves not retroflexed .............................. C. sessilifolia Mart.

- Leaves oblong, oblanceolate to narrow-lanceolate, base obtuse, when cordate, basal leaves retroflexed ..................................... 49

49. Leaves 25–40 mm long, the basal leaves retroflexed ................................................................. C. melampyrifolia Pohl ex Koehne

- Leaves 8–30 mm long, the basal leaves not retroflexed .............................................................................. C. antisyphilitica Kunth

50. Pedicels 3–6 mm long, persistent ....................................................................................................................... C. acinos A.St. -Hil.

- Pedicels 1–3 mm long, not persistent ............................................................................................................................................. 51

51. Stems with green glandular trichomes; petals discolorous, the 2 dorsal petals deep purple, the 4 ventral petals lilac; floral tube dorsally slightly concave, mouth upturned, slightly oblique ............................................................. C. glutinosa Cham. & Schltdl.

- Stems with red-purple glandular trichomes; petals concolorous, white to lilac; floral tube straight, mouth not upturned.................. ................................................................................................................................................................ C. ingrata Cham. & Schltdl.

52. Plants decumbent, prostrate; ovules ca. 11; floral tube with rectangular shape in fructification .............. C. polymorpha A.St. -Hil.

- Plants erect; ovules 3–7; floral tube with tubular shape in fructification ....................................................................................... 53

53. Leaves narrowly lanceolate tending to become falcate; plants without xylopodium, not cespitose.................................................... ........................................................................................................................................... C. anamariae T.B.Cavalc. & S.A.Graham

- Leaves ovate to ovate-oblong, elliptic or oblanceolate, not falcate; plants with xylopodium, usually cespitose .......................... 54

54. Leaves all or in part appearing uni-veined ................................................................................................ C. hyssopoides A.St. -Hil.

- Leaves distinctly pinnately-veined ................................................................................................................................................. 55

55. Leaves mostly 3–4-verticillate; ovules 3; infrastaminal vesicles 8–10 ..................................................... C. spermacoce A.St. -Hil.

- Leaves opposite; ovules 5–7; infrastaminal vesicles 0 ........................................................................... C. brachypoda T.B.Cavalc.