Copyright 1998. Taxonomic Computer Research. All Rights Reserved. May not be duplicated on paper or disk media without written permission.
Copyright 1998. Taxonomic Computer Research. All Rights Reserved.
May not be duplicated on paper or disk media without written permission.
1. Plants scandent (vining) & ovary always inferior.....2
1. Plants erect (shrubby) & ovary inferior or superior.....10
2. leaves evergreen, only fertile flowers exist.....3
2. leaves deciduous, fertile & sterile flowers occur.....4
3. POSSIBLE ID=Hydrangea serratifolia
4. stamens 9 - 15 (uncommon in gardens).....5
4. stamens 15 - 20 (common garden form).....6
5. POSSIBLE ID=Hydrangea anomala subsp. anomala
5. POSSIBLE ID=Hydrangea anomala subsp. petiolaris
10. inflorescence an erect or conical cluster.....11
10. inflorescence a flat-topped cluster.....20
11. leaves pinnately lobed & ovary inferior.....12
11. leaves unlobed & ovary half-inferior.....13
12. POSSIBLE ID=Hydrangea quercifolia & cultivars
13. POSSIBLE ID=Hydrangea paniculata
20. ovary inferior in fruit and flower.....21
20. ovary half-inferior in both flower & fruit.....40
20. ovary inferior in flower & half-inferior in fruit.....50
21. bract broadly ovate to orbicular & capsules pubescent.....22
21. bract lanceolate to narrowly ovate & capsule glabrous.....23
22. POSSIBLE ID=Hydrangea involucrata
23. fertile flowers blue, densely hirsute.....24
23. fertile flowers white, hairs scattered.....30
24. velutinous & fleshy trichomes, lvs. 15 - 25 cm wide.....25
24. velutinous & strigose below , lvs. 5 - 35 cm wide.....26
24. velutinous , lvs. 9 - 25 cm wide.....27
25. POSSIBLE ID=Hydrangea aspera subsp. sargentiana
26. petioles 5 to 17 cm long, ovate to broadly ovate.....28
26. petioles 1 to 5 cm long, lanceolate to narrowly ovate.....29
28. POSSIBLE ID=Hydrangea aspera subsp. robusta
29. POSSIBLE ID=Hydrangea aspera subsp. strigosa
27. POSSIBLE ID=Hydrangea aspera subsp. aspera
30. leaves green & glabrous below except on midrib below.....31
30. leaves grey & densely pubescent below.....32
30. leaves white & densely tomentose below.....33
33. POSSIBLE ID=Hydrangea arborescens subsp. radiata
31. POSSIBLE ID=Hydrangea arborescens subsp. arborescens
32. POSSIBLE ID=Hydrangea arborescens subsp. discolor
40. POSSIBLE ID=Hydrangea heteromalla
50. petals 3-4 mm, capsules 6-8 mm; leaves glabrous, glossy.....51
50. petals 2-3 mm, capsules 3-6 mm; leaves pubescent, dull .....52
51. POSSIBLE ID=Hydrangea macrophylla subsp. macrophylla
52. POSSIBLE ID=Hydrangea macrophylla subsp. serrata
51. all flowers sterile.....53
51. flowers both sterile and fertile in 1 inflorescence.....54
53. POSSIBLE ID=Hydrangea macrophylla subsp. macrophylla f. macrophylla
54. POSSIBLE ID=Hydrangea macrophylla subsp. macrophylla f. normalis