Plant Collection and Preservation Techniques
Explore the process of collecting and preserving plant materials for herbarium preparation. Learn about the importance of plant documentation, including dry and wet preservation methods. Understand why plant collection is crucial for systematics studies and serving as a reference collection for named taxa. Discover the guidelines on what to collect and how to properly collect different types of plant specimens.
- Plant Collection
- Preservation Techniques
- Herbarium Preparation
- Systematics Studies
- Plant Documentation
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LAB 2 Collection and Preservation of Plant materials and Herbarium preparation
Plant Collecting and Documentation Collections: Samples of plants Dried or liquid preserved. Kept alive, grown in greenhouse or garden
Preservation is of types: 1. Dry Preservation/Herbarium: A collection of dried plant specimen mounted on sheet is known as Herbarium. 2. Wet Preservation: Very fleshy and delicate structures, including small algae are best preserved in air tight Glass jars with liquid preservatives.
Why collect? 1) Provide systematics studies. 2) Serve as a reference collection for named taxa, known as a voucher specimen. a) Type specimen in formal naming b) Reference for the identity of a taxon -in systematic studies -in field studies, e.g., floristic surveys 3) Provide information about the plant in a native habitat: put info. in database resource material for plant
Should you collect? What to collect? Generally DON T collect listed taxa: rare, endangered, or threatened Must know ahead of time which these are! When you collect, use 1 to 20 rule: For every herb you collect, make sure there are at least 20 in the population. For every branch of a shrub or tree, make sure there are at least 20 more.
How to collect? Herbs: Must dig up at least one entire plant to show root or rootstock (e.g., corm, bulb, rhizome) Shrubs, trees, vines: One branch sufficient. Collect a representative specimen that shows vegetative and reproductive parts (in flower, fruit, cone, with sporangia, etc.)
Plant Press Cardboards: ca. 12 x 18 Newspaper, ca. 11.5 x 16.5 Tighten straps Place in plant drier, 2-3 days Remove and check if dry (if it feels cool, not dry)
Liquid-Preserved Collections Anatomy, embryology, palynology, etc.: FAA (Formalin - Acetic Acid - Alcohol (ethanol) Cytology (chromosome numbers): Carnoy s (100% ethanol : glacial acetic acid) Living Collections : Grow in greenhouse or botanic garden Valuable for long-term studies
How to make a Herbarium? 1) Collecting the plants 2) Pressing and Drying 3) Mounting
1) Collecting the plants Choose good representatives of the plants species Be careful that these plants must include root, stem, flower and fruit Take notes and record by taking photos in the field at the time of collection, Note these factors below: Date, collection number, location, habitat, habit, special characteristics
1) Collecting the plants Choose good representatives of the plants species Be careful that these plants must include root, stem, flower and fruit Take notes and record by taking photos in the field at the time of collection, Note these factors below: Date, collection number, location, habitat, habit, special characteristics
Collect specimens in dry conditions, a good time being mid-morning, after the dew has dried but before the heat of the day causes plants to wilt. If specimens are at all wet or you need to wash soil off the roots then dry them carefully before pressing. Use a pencil for these notes rather than a pen because any damp/wetness can cause ink to smudge and be unreadable
Materials for plant collecting: Plant press Plastic bags or nylon bag Garden secateurs & trowel Small note book & pencil Jeweller s tags (optional) Camera (optional) GPS & altimeter (optional)
PRESSING & DRYING - Plants must be clean before pressing - They must also be put in a plastic bag or nylon bag, if it is hot they must be watered to be fresh - Place your plant between folded-out sheets of newspaper, although flimsy or greaseproof paper is preferable for delicate material - Arrange the plant carefully, trying to avoid overlapping. - When you have finished arranging the specimens within the newspaper sheets (or whatever combination of papers you have chosen), you then need to intersperse them between corrugated card sheets to aid ventilation. - Finally place everything in your press and tighten well.
For the first two to four days you will need to check daily and change the blotting paper and/or other surrounding papers, and retighten the press, but as the plants dry these checks can become less frequent. Warmth may be used to improve the drying rate, An oven set at 50 C may be used but the heat must be no higher, otherwise the specimen will become very brittle and damaged.
MOUNTING Cartridge paper for mounting your specimens should preferably be A3 size and acid-free; the weight should be a minimum 180g/m2, and ideally with a rough textured surface Using only one side of your thick A3 cartridge paper, arrange your specimens carefully, making sure that they represent the way the plant grows naturally
Example Herbarium Label Scientific name: Ranunulaceae, Ranunculus ficaria (family, genus and species) Vernacular name(s): Lesser Celandine, Pilewort Collector s name and specimen number: Lawrence 1 Date of collection: 20th March 2003 Locality: Orleans House Gardens, Twickenham, England Habitat: damp, clay soil, 20 yards from riverbank, growing in dappled shade on the edge of deciduous woodland; nearby plant is Dock (Rumex obtusifolius). Habit: perennial herb, up to 20 cm tall, with stems creeping and rooting Characteristics: leaves hairless glossy green, flowers bright glossy yellow, turning white with age
Exercise 2 Prepare 2 herbarium sheet with their description.
