Dalbergia

Ramanantsialonina, Ravo Nantenaina, Sandratriniaina, Ninah Andrianasolo, Rakouth, Bakolimalala, Wiemann, Michael C. & Ravaomanalina, Bako Harisoa, 2024, Comparative anatomy of young stems and leaves of 16 Dalbergia species (Fabaceae) from Madagascar and their taxonomic significance, Phytotaxa 652 (1), pp. 33-46 : 42

Identification key for the 16 studied Malagasy Dalbergia

The following identification key for the 16 Malagasy Dalbergia species is based on qualitative features that are easy to observe: the shape of the lamina, the pattern of vascularization in the petiole, presence or absence of papillae, hypodermis and its type, arrangement and disposition of bundle sheath.

1a Shape of lamina: Flat-flat .................................................................................................................................................. D. lemurica

1b Shape of lamina: other........................................................................................................................................................................2

2a Presence of papillae in lower epidermis.............................................................................................................................. D. baronii

2b Lower epidermis lacking papillae ......................................................................................................................................................3

3a Hypodermis present at mesophyll .................................................................................................................................... D. greveana

3b Hypodermis absent at mesophyll........................................................................................................................................................4

4a Palisade parenchyma in all mesophyll .................................................................................................................... D. razakamalalae

4b Palisade parenchyma only on the adaxial side of mesophyll .............................................................................................................5

5a Bundle sheath Type I (parenchyma thin-walled irregularly shaped)..................................................................................................6

5b Bundle sheath Type II (parenchyma thick-walled and rounded)......................................................................................................14

6a Bundle sheath Type I on the left and right-sides of the vascular bundles ................................................................. D. purpurascens

6b Bundle sheath Type I surrounding the vascular bundle......................................................................................................................7

7a Bundle sheath Type I partially surrounding the vascular bundle .......................................................................................................8

7b Bundle sheath Type I completely surrounding the vascular bundle ................................................................................................ 12

8a Open arc vascular bundles with one adaxial vascular bundle at proximal part of petiole .................................................. D. urschiii

8b Open arc vascular bundles at proximal part of petiole .......................................................................................................................9

9a Simple open arc vascular bundles at proximal part of petiole........................................................................................... D. oronjiae

9b Open arc vascular bundles with slightly incurved ends at proximal part of petiole.........................................................................10

10a Open arc vascular bundle at distal part of petiole ................................................................................................................ D. davidii

10b Vascular bundle clearly separated at distal part of petiole ...............................................................................................................11

11a Vascular bundle clearly separated into 5 at distal part of petiole ................................................................................... D. abrahamii

11b Vascular bundle clearly separated into 6 to 9 at distal part of petiole ......................................................................... D. chlorocarpa

12a Closed arc vascular cylinder at distal part of petiole....................................................................................................... D. monticola

12b Open arc vascular bundles at distal part of petiole...........................................................................................................................13

13a Simple open arc vascular bundle at proximal part of petiole ................................................................................... D. pseudobaronii

13b Open arc clearly separated into five vascular bundles at proximal part of petiole ............................................................... D. bathiei

14a Bundle sheath Type II completely surrounding the vascular bundles............................................................................. D. orientalis

14b Bundle sheath Type II on abaxial side..............................................................................................................................................15

15a Open arc with one adaxial vascular bundles at distal part of petiole ............................................................................. D. normandii

15b Vascular bundle clearly separated into 6 to 9 at distal part of petiole .................................................................................. D. obtusa