The xeromorphic adaptation of epidermal cells of Lamiaceae plant leaves, the conse­ quence of their adaptation to an arid habitat, was investigated. These xerophytic species inhibit transpiration in different ways, depending on the number, the form and the position of trichomes, whether they are dead hairs or live glandular structures. The Salvia genus is characterized on one hand by multicellu...

Hypodematium confertivillosum J.X.Li, F.Q.Zhou & X.J.Li, sp. nov., a new species of Hypodematium from Shandong, China, is described and illustrated. It is similar to H. crenatum (Forssk.) Kuhn & Decken and H. glanduloso-pilosum (Tagawa) Ohwi, but differs greatly from them by its abaxial fronds sparsely covered with rod-shaped glandular hairs, its adaxial fronds without rod-shaped glandular hair...

Secreting glandular plant trichome types which accumulate large quantities of metabolic products in the space between their gland cell walls and cuticle permit the plant to amass secretions in a compartment that is virtually outside the plant body. These structures not only accumulate and store what are often phytotoxic oils but they position these compounds as an apparent first line of defense...

As often reminded to the readers in articles or reviews which deal with plant adaptation to their environment, higher plants are sessile organisms, a life habit which does not allow them to escape danger or to move to avoid adverse conditions. This environmental pressure has led to a myriad of adaptations, which are reflected in the vast diversity of plant habitats, morphologies, life cycles an...

Trichomes are epidermal hairs found on the aerial surfaces of nearly all plants and in different species. They grow in different shapes and act as protectors against insects, microbes and herbivores. Trichomes vary in their morphology, distribution pattern on a given organ and in their histochemical images. Different trichome types were observed in the aerial parts of the two species of broomra...

Long-stalked glandular hairs of outer and inner involucral bracts of Sigesbeckia jorullensis, which are important for epizoic fruit propagation, were investigated using light and scanning electron microscopy. The essential oil secreted by the hairs was analysed by chromatographic methods including gas chromatography/mass spectrometry and with a laser microprobe mass analyser. The glandular hair...

Two new and peculiar species of Heteranthera are herein described. Heteranthera catharinensis is unique in the genus due to its glomerulate, many-flowered inflorescences, in which the flowers are restricted to the base and apex of the cincinni. It also possesses the biggest flowers in the H. reniformis Ruiz & Pavón species complex, with glabrous perianth lobes, medial filament, and style. On th...