FRIENDS OF EDGEWOOD NATURAL PRESERVE
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FRIENDS OF EDGEWOOD NATURAL PRESERVE
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INTRODUCTION TO PLANT FAMILIES By Toni Corelli This is the first of a series of articles about flowering plant families. —ed. In the Flowering Plants of Edgewood Natural Preserve, referred to as “the Flora” for this series, the plants are arranged alphabetically by family. This is also the arrangement used in The Jepson Manual. Alphabetical ordering provides no information about relationships between families, or genera within families. Some floras place the plants in order of phylogenetic classification (based on their assumed evolutionary history and relationships). This is how the plants are arranged in the Flora of the Santa Cruz Mountains. Some of the floral characteristics used to show relationships within families are: the number of sepals; number of petals; number of stamens; number of stigmas; whether the sepals and/or petals are fused; the position of the ovary (above or below the sepals); and other floral structure characteristics. Secondary characteristics are also used such as: leaf arrangement; flower arrangement; fruit structure including the number of seeds and chambers within the ovary. All true plants are considered to be members of the Kingdom Plantae. The Flora excludes the “lower” true plants, which lack a vascular system (algae, mosses and liverworts). The vascular plants can be broken into three main groups of one or more Divisions: 1) ferns and fern allies, which produce spores; 2) gymnosperms, woody plants that reproduce by seeds not enclosed in an ovary (seeds are borne in cones); and 3) flowering plants, which produce flowers and develop their seeds enclosed in an ovary. Flowering plants make up about 95% of California’s higher plants. Their two main classes are: dicots (Dicotyledones) and monocots (Monocotyledones). All family names end with the letters “aceae” (meaning belonging to or having the form of), for example Asteraceae. The other part of the family name is the name of a genus within that family, such as the genus Aster in the family Asteraceae. Let’s look at scientific nomenclature1 as it relates to a plant we might be familiar with:
The Jepson Manual lists 173 families occurring in California. The Flora has 72 families, or 42% of all of the families in California. In terms of number of species in California, the Sunflower Family has the most species. It is of no surprise then, that it is also the largest family at Edgewood. The plant family with the most species worldwide is the Orchidaceae (Orchid) Family. All of this is not set in stone. Those of you who have been learning about plants have seen many plant name changes within the last twenty years. These changes do not just occur randomly but are based on the scientific study of individual species that are then ratified at a Botanical Congress (these take place every four years). Look for future changes on the web at “Tree of Life” and “Deep Gene,” both of which are referenced on the “Deep Green” web (see references). It looks like there will be a whole new classification system based mainly on genetic and chemical details. Idea Come up with something that will help you remember the order of the Cronquist plant classification system: Kingdom; Division; Class; Subclass; Order; Family; Genus; Species; Common name; (K,D,C,S,O,F,G,S,C):. E-mail me at corelli@coastside.net and we will see what we come up with. References Cronquist, A. 1981. An Integrated System of Classification of Flowering Plants. Columbia University Press. Corelli, Toni 2002. Flowering Plants of Edgewood Natural Preserve. Monocot Press. Hickman, J.C., editor. The Jepson Manual: Higher Plants of California. University of California Press. Thomas, J.H. 1961. Flora of the Santa Cruz Mountains of California. Stanford University Press. Cronquist System: http://www.csdl.tamu.edu/FLORA/newgate/cron1ang.htm Deep Gene: http://ucjeps.berkeley.edu/bryolab/deepgene/ Deep Green: http://ucjeps.berkeley.edu/bryolab/greenplantpage.html Nomenclature: http://www.calflora.net/botanicalnames/nomenclature.html 1 Based on the “Cronquist System” of plant classification. |
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