Bioloy of Orchids

general courses

Classroom

The aim of the subject is an introduction to floral biology, systematics and ecology of selected groups of Orchids. The course focuses on following topics: morphology of epiphytic and terrestrial orchids and their adaptations to various habitats; relationships between orchids and fungi; floral morphology; sexual reproduction in Orchids; putative evolution of pollination systems, and reasons why deceptive flowers are so common. The lectures also refer to Orchidaceae systematics, their geographical range and distribution of main groups of Orchids. It also highlights practical aspects of cultivation and conservation especially the question why they are so rare.

The aim of the course is an introduction to biology of flowers, systematics and ecology of selected groups of Orchids. The course focuses on problems of origin of the family, evolution, descriptive morphology and morphological adaptations of vegetative organs of epiphytic and terrestrial forms to various type of habitats. Also, relationships between fungi and orchids are raised.

The parts relating to the flowers and sexual reproduction comprise morphology of the flower, pollination and some aspects of embryology typical for the family. Biology of pollination include system of pollination with emphasis on specialization and deceptive orchids.

Introduction to systematics of Orchids presents historical and present state of studies. Furthermore, biology of the most representative groups for particular geographical regions are presented.

Practical aspects of cultivation comprise micro-propagation, types of subsoil, nutrition and watering, appropriate light and temperature conditions. This part is connected with visits in greenhouse of Botanic Garden.

Conservation of orchids include aspects of CITES regulations.

Topics

1. History of the Orchidology. Morphological characteristics of the family. Growth habits. Vegetative organs: aerial roots, rhizomes and underground bulbs. Stems: rhizome, corms and pseudobulbs. Types of the growth. Leaves: arrangement and modifications.

2. Inflorescences and flowers. Types of inflorescences. Morphology of the flower. Resupination. Variations in the structure of perianth, determination of development. Structures and glands connected to perianth: nectaries, osmophores and elaiophores – functions. Gymnostemium, anther and staminodia. Pollen dispersal units, structure of pollinarium. Structure of stigma and rostellum. Factors determining efficiency of pollen transfer, deposition and fruit set. Origin of Orchidaceae family. What group of plants are the Orchids most closely related to? Primitive features in the Orchidaceae. Probable evolution of some vegetative and generative features.

3. Reproductive strategies in Orchids. Choice between outcrossing and selfing. Coevolution of Orchids and pollinators. Pollination syndromes. Consequences of extremely specialized strategies in pollination. Examples of ombrophily and anemophily in orchids. Why about ¼ Orchids are deceptive?

4. Embriology of Orchids. Flower longevity, receptivity of stigma, pollen viability. Factors influencing reproductive success. Pollination and fertilization. Development of the ovule. Structure of seed and embryo.

5. Orchids and fungi. Seed germination. Protocorm development. Why Orchids need fungi, relationships between Orchids and fungi. Myco-heterotrophic Orchids and relationships between ectomycorhizal and saprophytic Basidiomycetes. Mixotrophy in orchids.

6. Systematics of Orchids. History of researches on systematics of Orchidaceae. Recent systematics of the family; subfamilies Apostasioideae, Cypripedioideae, Vanilloideae, Orchidoideae i Epidendroideae.

7. Orchids of Old World. Tropical Asia. Selected representatives of tribes Podochileae: subtribe Dendrobiinae, genus Dendrobium; Bulbophyllinae and pantropical genus Bulbophyllum. Tribe Vandeae, subtribe Aeridinae genus Phalaenopsis, Aerides and Vanda.

8. Orchids of Australia, New Zeland and New Caledonia. Tribe Diurideae. Sexual deception in Chiloglottis, Cryptostylis, Calochilus, Caleana, Drakea and Leporella. Life-style of Rhizanthella gardneri – underground and mycoheterotrophic Orchid. Trap flowers in Pterostylis.

9. Orchid flora of Africa, Madagascar and Mascarene Islands. Pollination in genus Angraecum. Evolution of pollination in Disa and Satyrium.

10. Orchids of temperate zone: Europe/Asia. Polish Orchid flora. Pollination strategies in Platanthera, Dactylorhiza, Cypripedium, Epipactis and Ophrys. Is sexual deception in Ophrys a kind of parasitism? Mycoheterotrophic Limodorum and Neottia.

11. Orchids of America. Subtropical America. Mutualistic relationships between orchids and orchid bees.

12. Orchids of South America. Tribe Epidendreae. Selected representatives of subtribe Pleurothallidinae: Pleurothallis, Masdevallia, Dracula and subtribe Laelinae: Brassavola, Cattleya, Epidendrum and Laelia. Tribe Cymbidiae and selected representatives of subtribe Oncidiinae: Brassia, Gomesa Oncidium and Lockhartia. Selected representatives of tribe Maxillarieae, genus Maxillaria, Stanhopea and Zygostates.

13. Practical aspects of cultivation of Orchids. Subsoil used in cultivation. Temperature and light conditions. Watering. Difficulties in micro-propagation. Collection of Orchids in Botanic Garden UW.

14. Orchids as economic plants. Cultivation of Vanilla. Orchids in traditional and conventional medicine.

15. Protection of Orchids. Why are they so rare? Protection of habitats and mutualistic interactions. Orchids in the Washington Convention (CITES).

Dressler R. L. 1993. Phylogeny and classification of the orchid family. Cambridge University Press.

Harder L.D. & Barrett S.C.H. (eds.) 2006. Ecology and evolution of flowers. Oxford University Press, Oxford.

Proctor M., Yeo P. & Lack A. 1996. Natural History of Pollination. Harper Collins Publishers, London.

la Croix I. 2008. The New Encyclopedia of Orchids: 1500 Species in Cultivation. Timber Press.

van der Cingel N. A. 2001. An Atlas of Orchid Pollination: European Orchids. A.A Balkema Publishers.

van der Cingel N. A. 2001. An Atlas of Orchid Pollination: America, Africa, Asia and Australia. A.A Balkema Publishers.

Dixon K., Kell S., Barrett R.& Cribb P. 2003. Orchid Conservation. Natural History Publications (Borneo).

Kubala T., Kusibab T., Szlachetko D. 2008. Orchidee: amatorska uprawa storczyków. Multico.

KNOWLEDGE student knows:

- morphology of vegetative organs

-morphology and evolution of the flower in Orchidaceae

-process of pollination and fertilization

-relationships between Orchids and fungi

-systematics of the family and distribution main groups of Orchids

-cultivation conditions of orchids

- why Orchids are rare plants and how they are protected

SKILS student can

- indicate adaptations of Orchids to various habitats

-indicate floral features typical for the family and morphological adaptation of the flower to pollination

-indicate distribution of main groups of Orchids

- use scientific literature

SOCIAL COMPETENCE

-necessity of continuous actualization of knowledge;

-understanding problems of protection of rare plants;

Test examination