Curcuma

S., Saensouk, T., Boonma & Saensouk, P., 2022, Curcuma achrae (Zingiberaceae), a new species from Central Thailand, Rheedea 32 (1), pp. 30-45 : 37-42

Key to the species of Curcuma in Thailand

1. Epigynous glands absent (subgen. Hitcheniopsis) .................................................. 2

1. Epigynous glands present .......................... 24

2. Bracts not laterally connate, campanulate involucre with two slits ................................ 3

2. Bracts laterally connate to each other for about half of their length and forming basal pouches ........................................................................ 6

3. Bracts purplish-brown .......... C. macrochlamys

3. Bracts green or red ........................................ 4

4. Leaves glabrous adaxially, pubescent abaxially; bracts green with dense stripes from the base to apex or red.............................. C. pedicellata

4. Leaves glabrous on both surfaces; bracts green ........................................................................ 5

5. Leaves 2–3, lanceolate; flowers 15–20 ........... .................................................. C. campanulata

5. Leaves 4–5, oblanceolate-oblong; flowers 6–8 .................................................... C. involucrata

6. Inflorescence without coma ......................... 7

6. Inflorescence with well-developed coma .. 15

7. Bracts pink with green or purple at the tip, or reddish-brown with green margin................8

7. Bracts pale green to dark green .................. 10

8. Labellum light purple to purple, basally with two bright to dark red thick bands (one on each side), distally pale to bright purple, median band only slightly darker than remainder of labellum ........................................ C. lithophila

8. Labellum not purple as above ....................... 9

9. Bracts pink with green or purple at tip, apex acute; labellum pale to dark red with bright yellow patches on the bright red swollen band at the base half of the labellum, yellow towards the apex .................................. C. sparganiifolia

9. Bracts reddish-brown with green margin, apex rounded; labellum white with pink apex and yellowish band in centre ..................... C. bella

10. Bracts puberulent on both sides ..................... .................................................. C. papilionacea

10. Bracts glabrous on both sides ..................... 11

11. Labellum with prominently fimbriate margins, fimbriae c. 1.5 mm long, curly .... C. fimbriata

11. Labellum not fimbriate at margins ............. 12

12. Bracts lanceolate, with upper half, suddenly narrowed to acute apex............... C. harmandii

12. Bracts almost orbicular or broadly ovate or broadly obovate ........................................... 13

13. Flowers slightly exserted from bracts; bracts almost orbicular ............................... C. prasina

13. Flowers exserted from bracts; bracts broadly ovate or broadly obovate ............................ 14

14. Labellum with two dark yellow spots at base and a small pale-yellow line at mid lobe from sinus almost to base; bracts broadly ovate; staminodes pale pinkish purple to pale purple with white at base ......................... C. charanii

14. Labellum without two dark yellow spots at base, with short yellow dashes along each side of incision margin about half-length; bracts broadly obovate; staminodes white............... .................................................. C. puangpeniae

15. Labellum red................................................ 16

15. Labellum not red ......................................... 20

16. Staminodes pale purple or violet ................ 17

16. Staminodes yellow or white ....................... 18

17. Anther spurred, L-shaped, connective white to cream, sometimes very pale purple dorsally, covered with short glandular hairs ................. ..................................................... C. rufostriata

17. Anther not spurred ........................ C. rhabdota

18. Labellum yellow with red lines; staminodes pale yellow to yellow with red tinge ............. ...................................................... C. gracillima

18. Labellum white with red; staminodes white with red........................................................ 19

19. Fertile bracts light green with two white circle patches and light pale green or white longitudinal line; coma bracts outer light green with green longitudinal line alternating with light green or white lines, inner white with green edges .............................. C. saraburiensis

19. Fertile bracts pale green to cream without white circle patches and without longitudinal line; coma bracts white .............. C. spathulata

20. Coma bract pink ..................... C. alismatifolia

20. Coma bract green or white ........................ 21

21. Fertile bracts green with rich reddish-brown tinge ............................................. C. micrantha

21. Fertile bracts green without reddish-brown tinge ............................................................. 22

22. Corolla tube longer than bract, flower distinctly protruding from the inflorescence; staminodes white; coma bracts green on both surfaces ........................................ C. purpurata

22. Corolla tube shorter than bract; staminodes purple or violet; coma bracts white or with green ............................................................ 23

23. Labellum deeply bilobed; coma bracts pure white ................................................ C. thorelii

23. Labellum with fringed edge; coma bracts white with green at apex ....................... C. parviflora

24. Inflorescences lacking a conspicuous coma of sterile bracts, fertile bracts connate only at the base, open flower form; anther spurs filamentous or conical, forward-pointed (subgen. Ecomata) ....................................... 25

24. Inflorescences usually with a coma bract, closed flower form‚ bullet-type; anther spurs, flat, acute, downward-pointed or absent (subgen. Curcuma ) ...................................................... 46

25. Corolla tube longer than bracts, narrow; petioles very distinct from leaf blade.............. ................................................... C. supraneeana

25. Corolla tube shorter than bracts, broad; leaf-blade tapering into petioles ....................... 26

26. Anther spurs filamentous, 0.5–1.5 mm long. ...................................................................... 27

26. Anther spurs conical or cylindrical,> 2 mm long .............................................................. 31

27. Staminodes white with dark purple tips ........ ....................................................... C. pierreana

27. Staminodes white or white with yellowish patch in centre and apex ............................. 28

28. Leaves puberulous on both surfaces ............... .............................................. C. chantaranothaii

28. Leaves adaxially glabrous ............................ 29

29. Rhizomes creeping; leaf base attenuate .......... .............................................. C. cochinchinensis

29. Rhizomes ovoid; leaf base cuneate to rounded, or sub-cordate ............................................. 30

30. Calyx white, glabrous; filament 2 mm long; anther 8–9 mm long ....................... C. eburnea

30. Calyx pale purple, puberulent; filament 5–8 mm long; anther 2.5–4 mm long .... C. pitukii

31. Inflorescence terminal ................................. 32

31. Inflorescence lateral ..................................... 40

32. Leaves adaxially glabrous. ........................... 33

32. Leaves adaxially hairy along the veins or pubescent ..................................................... 37

33. Staminodes without red spots at the base ... 34

33. Staminodes with dark red or dark purple spots at the base .................................................... 35

34. Midrib adaxially green ................ C. rangsimae

34. Midrib adaxially red ..................... C. siamensis

35. Leaves abaxially glabrous; labellum yellow with inside half orange ............................ C. rhomba

35. Leaves abaxially pubescent; labellum not as above ............................................................ 36

36. Labellum sub-orbicular, white with an orange median band and deep purple lines at the base; staminodes white with orange tip .... C. woodii

36. Labellum diamond-shaped, white with a yellow median band and red spots at the base; staminodes white without orange tip ............ ..................................................... C. peramoena

37. Corolla lobes whitish-green to pale green; leaf base cuneate to attenuate .................... C. putii

37. Corolla lobes pink, red or purple; leaf base oblique, rounded or cordate ....................... 38

38. Staminodes dark red in the lower half, upper half orange-yellow ........................... C. bicolor

38. Staminodes pale yellow to yellow .............. 39

39. Thyrse < 10 cm long; flowers open form; corolla lobes red .......................... C. stenochila

39. Thyrse> 10 cm long; flowers closed form; corolla lobes white to yellow.... C. cinnabarina

40. Staminodes purple .......................... C. ecomata

40. Staminodes white or yellow ....................... 41

41. Labellum yellow .......................................... 42

41. Labellum white with yellow median band .... ...................................................................... 44

42. Anther almost straight in sideview; staminodes with reddish V-shaped or triangular patch at the base .............................................. C. achrae

42. Anther L-shaped in sideview; staminodes without red patch as above ......................... 43

43. Staminodes ovate to elliptic; leaf base cuneate ....................................................... C. flaviflora

43. Staminodes obovate; leaf base rounded ......... ............................................................ C. aruna

44. Leaves adaxially with red patch along the midrib .............................................. C. candida

44. Leaves adaxially with green midrib ........... 45

45. Staminodes white ......................... C. singularis

45. Staminodes lower half white, upper half yellow, central with purple patch ..... C. glans

46. Rhizome not branched ............................... 47

46. Rhizome branched ..................................... 49

47. Inflorescence lateral and terminal .................. ................................................... C. angustifolia

47. Inflorescence terminal ................................ 48

48. Sheaths glabrous; leaf abaxially glabrous ....... ........................................................... C. plicata

48. Sheaths pubescent; leaf abaxially hairy or glabrescent at least at the apex .... C. attenuata

49. Inflorescence terminal ................................ 50

49. Inflorescence usually lateral ........................ 60

50. Rhizome creeping ................. C. rubrobracteata

50. Rhizome with branches non-creeping ...... 51

51. Anther ecalcarate ......................................... 52

51. Anther calcarate........................................... 53

52. Flowers yellow or orange-yellow .................. ..................................................... C. aurantiaca

52. Flowers cream-white with yellow median band .............................................. C. roscoeana

53. Bracts glabrous. ........................................... 54

53. Bracts pubescent .......................................... 55

54. Ovary glabrous ............................... C. antinaia

54. Ovary pubescent ................. C. sattayasaiorum

55. Coma bracts greenish-white ...... C. viridiflora

55. Coma bracts pink or white with pink at tip .. ...................................................................... 56

56. Peduncle red .............................. C. phrayawan

56. Peduncle green ............................................ 57

57. Ovary glabrous .............................. C. petiolata

57. Ovary pubescent ......................................... 58

58. Leaves reddish-purple along the midrib adaxially ................................. C. wanenlueanga

58. Leaves green along the midrib adaxially ... 59

59. Rhizome pale yellow with the smell of green mango ............................................... C. amada

59. Rhizome deep orange-yellow without the smell of green mango ........................ C. longa

60. Leaves abaxially pubescent ......................... 61

60. Leaves abaxially glabrous ............................ 65

61. Leaves adaxially green with green midrib .. 62

61. Leaves adaxially green with red or reddish-purple patch along the midrib .................... 63

62. Rhizome yellow; lamina broadly lanceolate .. ...................................................... C. aromatica

62. Rhizome pale yellow; lamina oblong .......... .............................................................. C. elata

63. Bracts glabrous ......................... C. zedoaroides

63. Bracts pubescent .......................................... 64

64. Inflorescence cylindrical,> 10 cm long; bracts green, short hairy on both surfaces ................ ......................................................... C. latifolia

64. Inflorescence almost globular, < 10 cm long; bracts bright green to brownish green with pale green venation, adaxially puberulent, abaxially glabrous ....................... C. globulifera

65. Petioles and leaf-sheaths reddish brown ........ ....................................................... C. rubescens

65. Petioles and leaf-sheaths green ................... 66

66. Leaves adaxially green with red or reddish-purple patch along the midrib ................... 67

66. Leaves adaxially green with green midrib .. 69

67. Rhizome aeruginous green........ C. aeruginosa

67. Rhizome yellow or orange ......................... 68

68. Corolla lobes whitish or with very slight pinkish shade; rhizome pale straw coloured to yellowish white ................................... C. picta

68. Corolla lobes conspicuously pink to reddish; rhizome deep bright orange to yellow-orange .................................................. C. zanthorhiza

69. Fertile bracts pale pink; rhizome pale ochraceous ....................................... C. comosa

69. Fertile bracts green; rhizome white to pale yellow............................................................70

70. Bracts glabrous .......................... C. leucorrhiza

70. Bracts minutely puberulous on both sides ...... ......................................................... C. mangga