Pyrolaceae
YASIN J. NASIR
National Herbarium, Pakistan Agricultural Research Council, Islamabad.
Perennial rhizomatous evergreen herbs. Leaves simple, cauline or basal, alternate, opposite or subverticillate, exstipulate. Flowers regular, hermaphrodite, (4-)5-merous, solitary and terminal or in racemes, bracteate or not. Calyx of 5 united or free sepals. Petals 5, free. Stamens 10, sometimes less; filaments adnate basally to the petals; anther dehiscence porose or longitudinal. Ovary superior, (4-)5-Jocular (sometimes incompletely so) with many ovules on axile placentas. Fruit a loculicidal capsule. Seeds many, very small, embryo with poorly differentiated cotyledons.
A family of 3 genera and 30 species, distributed mainly in the N. temperate regions. Closely related to the Monotropaceae and the Ericaceae. It differes from the former in the chlorophyllous habit and porose anthers and from the latter in the herbaceous habit and undifferentiated embryo. Represented in Pakistan by 3 genera and 3 species.
Acknowledgements: We are grateful to the United States Department of Agriculture for financing this research under PL-480, and to Mr. I.C. Hedge, Royal Botanic Garden, Edinburgh, for going through the manuscript.
