Leaf and green stem anatomy of the drought deciduous Mediterranean shrub Calicotome villosa (Poiret) Link. (Leguminosae)

Light and scanning electron microscopy were used to study leaf and stem fine structure of the drought deciduous green-stemmed Mediterranean shrub Calicotome villosa (Poiret) Link. (Leguminosae). Each leaf consists of three small obovate leaflets with abundant but small (16 μm length) anomocytic stomata on both surfaces. Adaxial surface exhibits more than double stomatal density (440±8 mm−2) than the abaxial one (185±4 mm−2). T-shaped trichomes (36±3 mm−2) are present only on the abaxial leaf surface. Leaves are unifacial, furnished with palisade parenchyma on both sides. The stem is characterized by raised ridges and grooves. Beneath the one-cell-layered epidermis sclerenchyma is found on ridges, whereas stomata and palisade chlorenchyma are found in grooves. Hairs are abundant, especially in grooves. Stem and leaf palisade chlorenchymas are structurally similar. According to these data, photosynthesis could be efficiently supported by the stem.