Leaf epidermal micromorphology of the genus Hypericum (hypericaceae) from Iran

Foliar micromorphological characters of 17 species of Hypericum L. belonging to five sections, Androsaemum (Duhamel) Godron, Hypericum, Hirtella Stef. (including 2 subsections: Platyadenum N. Robson et Stenadenum N. Robson), Taeniocarpum Jaub. et Spach. and Drosanthe (Spach) Endl. were examined using scanning electron microscopy (SEM). Based on the current result three types of epidermal cell shape (irregular polygonal, roughly regular rectangular and irregular elliptical); four types of papilla (triangular, with striate wall, finger and star shapes); two main types and three subtypes of epicuticular wax; seven type classes of outer stomatal and peristomatal rims/stomata ledge aperture; three types of wax distribution on the stomata rims/pore/epidermal cell and three types of inner stomatal rims variations (smooth, sinuolate and sinuolate-erose) were identified. The result revealed that leaf micromorphological evidences of Hypericum are taxonomically informative and can be used for separating different sections and species

Pollen morphology of the genus Potentilla (Rosaceae) in Iran

The pollen morphology of 28 species of the genus Potentilla (Rosaceae) and four related genera from Iran was examined using light (LM) and scanning electron microscopy (SEM). The pollen grains are radially symmetrical, isopolar to subisopolar, trizonocolpate and colporate. The shape of pollen grains in all the studied taxa varies from prolate-spheroidal to subprolate and prolate. The outline of the pollen grains is elliptical in equatorial view and triangular-circular in polar view. The size of the pollen grains is small to medium. Our results showed two main types of exine sculpturing. Among the studied pollen grain characters, shape and size are helpful evidences for separating different sections, while the exine sculpturing type provides limited taxonomic value

Leaf indumentum types in Potentilla [Rosaceae] and related genera in Iran

Indumentum types of the leaves in 31 species of Potentilla L. (Rosaceae) and four related genera, especially Tylosperma Botsch., Schistophyllidium (Juz. ex Fed.) Ikonn., Drymocallis Fourr. ex Rydb., and Sibbaldia L. from Iran were investigated. Indumentum ultrastructure was studied by scanning electron microscopy (SEM). SEM observation revealed three type classes based on leaf indumentum: 1) straight (appressed-erect); 2) straight-erect and crispate, and 3) crispate-floccose. The straight hair character (I type class) is widely distributed among all genera sampled and six sections of Potentilla. In contrast the crispate-floccose indumentum (III type class) is confined to all examined species of sections Speciosae and Pensylvanicae. While some sections especially Rectae (straight and straight-crispate hairs) and Terminales (straight-crispate and floccose-crispate) posses two indumentum type classes. The present survey shows that indumentum types are of systematic importance and may form good key characters for identification purposes