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herbarium making.ppt

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herbarium making.ppt

  1. 1. Field collections for the herbarium
  2. 2. Why collect? 1) Provide resource material for plant 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. 3. How does one: 1) Obtain a specific plant(s) for a research study - Use label information from herbarium specimens to find localities - Use maps to find likely habitats 2) Do a complete inventory of plants for a field survey or floristic study? - Collect and identify every plant in a region during different seasons and different years.
  4. 4. 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.
  5. 5. 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.)
  6. 6. How to collect? Press plants: Portable field press used in field Transfer to standard herbarium press 1) Fold to fit fill up area 2) Cut to fit & to prevent too much overlap; slice rootstocks; slice flowers, fruits to show morph. 3) At least one leaf up, one down 4) Collect extra material, if possible. 5) Divide into 2 or more sheets, if necessary.
  7. 7. 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) Plant Press
  8. 8. Herbarium card
  9. 9. Collection Data
  10. 10. Collection Data
  11. 11. Importance of recording color, even of pollen grains!
  12. 12. Liquid-Preserved Collections Anatomy, embryology, palynology, etc.: FAA (Formalin - Acetic Acid - Alcohol (ethanol) Cytology (chromosome numbers): Carnoy’s (100% ethanol : glacial acetic acid) Ultrastructure: Gluteraldehyde, osmium tetroxide, formalin
  13. 13. Living Collections Grow in greenhouse or botanic garden Valuable for long-term studies Collections for Molecular Studies DNA: dried in silica gel Allozymes: fresh material
  14. 14. 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”
  15. 15. • 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
  16. 16. 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)
  18. 18. 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.
  19. 19. • 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.
  20. 20. • Pressing:
  21. 21. • Pasting:
  22. 22. • Herbarium sheet:
  23. 23. How good collecting can make specimens quicker to mount and easier to preserve long term. 6 basic reminders:
  24. 24. 1. The herbarium sheet is 42 x 26.5 cm. Collect enough material to show variation, but remember that multiple pieces take much longer to mount.
  25. 25. Local newspapers may not be the same size as a herbarium sheet. If specimens are too big they will have to be trimmed or folded which again increases mounting time.
  26. 26. 2. Collect enough material, including some for the capsule.
  27. 27. A single fruit or flower may easily be lost or damaged …
  28. 28. … especially if specimens are not handled carefully.
  29. 29. If secured by glue, the fruit or flower may be less easy to view. Loose material for the capsule is vital if specimens are glued down.
  30. 30. 3. Arrange plants for pressing so that all important features are displayed.
  31. 31. A poorly pressed specimen of Pimpinella. Rearranging dried plant material for mounting is fiddly and time consuming. Poorly pressed material is also more prone to damage once in the herbarium.
  32. 32. The same Pimpinella specimen after mounting.
  33. 33. This specimen was pressed so that the flower visible in the right hand photo was completely hidden by a leaf.
  34. 34. Remember to press the specimen so that you can see both upper and lower surfaces of the leaves.
  35. 35. 4.Take care with fruits and flowers.
  36. 36. Use waxed paper to press flowers to prevent damaging fragile petals. The flower on the left has also been dried for too long or at too high a temperature.
  37. 37. The curled leaves of this poorly pressed specimen were very fragile. It had to be soaked and repressed before mounting, a time-consuming process!
  38. 38. 5. Reduce bulk as far as possible.
  39. 39. Remove excess foliage and split bulky fruits and roots whenever possible. Very bulky material is difficult to store in the herbarium.
  40. 40. This bulky root distorts the other specimens in the folder.
  41. 41. 6. Package specimens carefully.
  42. 42. Put small fruits in packets, or they may end up lost in the bottom of a box!
  43. 43. Use cardboard to support bundles of pressed specimens and store them in strong boxes (top left) to protect them before mounting.
  44. 44. This Gesner has been damaged in transit.
  45. 45. Summary: The ‘gold standard specimen’ for mounting and preservation: •fits the sheet •includes material for the capsule •has been pressed to display fruit and flowers •is not too bulky •arrives undamaged So it is quick to mount and easy to preserve.