Comparative anatomy of young stems and leaves of 16 Dalbergia species (Fabaceae) from Madagascar and their taxonomic significance Ramanantsialonina, Ravo Nantenaina Sandratriniaina, Ninah Andrianasolo Rakouth, Bakolimalala Wiemann, Michael C. Ravaomanalina, Bako Harisoa Phytotaxa 2024 2024-05-31 652 1 33 46 9CKHP L.f. [692,807,374,401] Magnoliopsida Fabaceae Dalbergia Plantae Fabales 9 42 Tracheophyta genus  The following identification key for the 16 Malagasy  Dalbergiaspeciesis 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 TypeI (parenchyma thin-walled irregularly shaped)..................................................................................................6  5b Bundle sheath TypeII (parenchyma thick-walled and rounded)......................................................................................................14   6a Bundle sheath TypeI on the left and right-sides of the vascular bundles .................................................................  D. purpurascens  6b Bundle sheath TypeI surrounding the vascular bundle......................................................................................................................7   7a Bundle sheath TypeI partially surrounding the vascular bundle .......................................................................................................8  7b Bundle sheath TypeI 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 TypeII completely surrounding the vascular bundles.............................................................................  D. orientalis  14b Bundle sheath TypeII 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