Flashcards in How plants are Identified and collecting Deck (29):
3 ways to accomplish Identification
Ue a key
Compare unknown to herbarium specimens
Consult and expert
4 things needed to properly observe plants
- hand lens (at least 10x)
- Pair of sharp-pointed forceps
- Dissecting needle
- Single edge razor blade
Things to observe
- woody or herbaceous? annual or perennial?
- flower parts
- # of sepals and petals. Fused or separate?
- # stamens. Attachment. Fusion of filaments or anthers.
- # of pistils, styles, stigmas of the gynoecium
- cross section, count locules, ovules. placentation type.
-longitudinal section. ovary position and fusion of the parianth
-distribution and kinds of surface coverings
…. Then you can key.
First modern key
Lamarck's (1805) Flora Francois
Provides correct identity of a specimen by process of elimination.
Use diagnostic characters.
Most are dichotomous (present two choices at each step, pair of choices = couplet).
Rules for preparing a key
2) 1st word of each lead should be identical
3) two parts of the couplet should be contradictory statements.
4) avoid overlapping ranges and vague generalities
5) Positive statements (don't use the word not)
6)Use readily observable features
7) Consecutive couplets should not begin with the same word
8) may need to provide two sets of keys (flowering vs. fruiting)
9) Couplets may be numbered or lettered, or left blank if indented.
Two types of keys
Indented (yoked) and Bracket (parallel)
Collecting equipment for everyone
Pocket knife / Pruning shears
Hand lens at least 10X
plastic jug w/ water
pencil / pen with indelible ink
Additional inters for professional collecting
Collecting vials and jars
FAA and Carnoy's fixing solution
11 1/2 x 16 inches
cardboard cut the same size as the press with the corrugates running the width of the cardboard (act as air vents)
Rules for arranging specimens
- Show as many characters as possible. leaves and reproductive structures essential.
- turn over some leaves to show both surfaces
-press so reproductive parts can be seen and counted (split open if petals fused)
- fold whole plants in an N V or W shape
- Press small herbs whole, including root
- fleshy parts should be sectioned along long axis
- Hard fruits and cones should be dried and places in paper bag with info on it
- collection number should be placed on lower right hand corner of newspaper
- Some are difficult to press and will do better after wilting a little
field notes should include:
Date, location, habitat, notes
labels should include:
Heading, scientific name, locality, Habitat, collector name, collection number, Date
Additional label info
Stamped on herb. sheet
Herbarium name and accession number
Collection of dried and pressed plants arranged in some order and available for reference or study
NY botanical garden
1,250 cases and 7.5 million specimens
Functions of Herbaria
1) standard reference collection
2) reference collection for plant course
3) training students in herb. practices
4) Documenting the presence of species (providing geologic range data)
5) samples of the flora of an area
6) pointing out classification problems
7) Providing plant material and data for analysis
8) preserving type specimens
Large collections arranged according to system of class. such as Engler & Prantl or Bentham & Hooker.
-heating or freezing
Keep sheets flat
do not leaf through - lift one at a time
Support the stack
Keep Heavy objects off spec.
use a long arm microscope
Society of herbarium curators newsletter
1962 - Norlyn L. Bodkin
20 cabinets, 17,000 specimens
Recorded patterns of variation within and between plant populations. Wanted to understand the nature of species.
Exploring the nature of species as stable entities
Oldest known herbarium specimen collected by Darwin