LEAF ANATOMY OF DOMBEYA AND NESOGORDONIA (STERCULIACEAE), EMPHASIZINGEPIDERMAL AND INTERNAL IDIOBLASTS

We studied leaf anatomy, using clearings, resin sections, and scanning electron microscopy, from mostly herbarium specimens of 123 species o f Dombeya and 11 species of Nesogordonia (Sterculiaceae). Species were placed in seven idioblast categories, ranging from those without any to single and bicelled epidermal forms to multicelled nodules and sing le mesophyll idioblasts. Idioblast contents are possibly mucilaginous, but were not identified. In these two genera the range of foliar idio blast morphology surpasses that known previously for the entire family . Leaves are dorsiventral with mostly abaxial anomocytic stomata and t ypical palisade and spongy layers; paraveinal mesophyll is lacking. Mi niature glandular (clavates, capitates) and nonglandular (mostly stell ate) trichomes occur. Prismatic crystals predominate; epidermal prisma tics and mesophyll druses are rare.