Fig. 3

GC content of the plastomes of Gastrodieae and other species. a, Relationships between the length and GC content of plastomes of species. Gastrodieae species, green colour. Gastrodia species, light green. Didymoplexis pallens, dark green. Other species, blue colour. 1: Epipogium roseum; 2: Sciaphila densiflora; 3: Gastrodia peichatieniana; 4: Gastrodia sp.; 5: Gastrodia shimizuana; 6: Gastrodia menghaiensis; 7: Gastrodia longistyla; 8: Gastrodia crispa; 9: Gastrodia uraiensis; 10: Gastrodia flexistyla; 11: Gastrodia javanica; 12: Gastrodia elata; 13: Gastrodia angusta; 14: Aphyllorchis montana; 15: Petrosavia stellaris; 16: Epipogium aphyllum; 17: Didymoplexis pallens; 18: Neottia acuminata; 19: Neottia camtschatea; 20: Cymbidium bicolor; 21: Nervilia aragoana; 22: Epipactis veratrifolia; 23: Nervilia fordii. b Overall GC content and GC content of the first, second, and third positions of codons (GC1, GC2, and GC3, respectively) in the plastomes of various species. 1: Gastrodia menghaiensis; 2: Gastrodia peichatieniana; 3: Gastrodia longistyla; 4: Gastrodia shimizuana; 5: Gastrodia sp.; 6: Gastrodia crispa; 7: Gastrodia flexistyla; 8: Gastrodia uraiensis; 9: Gastrodia angusta; 10: Gastrodia elata; 11: Gastrodia javanica; 12: Didymoplexis pallens; 13: Nervilia aragoana; 14: Nervilia fordii