|Pam Photographing Primula agleniana in Tibet|
There are several key characteristics that when photographed can be helpful in identifying and documenting a species:
Flowers: Since the flower face is the prettiest part of the plant, it is the most photographed. Images can show useful details such as whether the flower is annulate or not, the position of the style, farina presence, hairs in the throat, petal shape and color patterns surrounding the eye. If the flowers are hanging, then don't forget to tilt the flower up to see the face! A thorough study would include splitting the flower open to see inside. It is rare that a single image of the flower face is enough to identify a species.
|Flower faces (L to R): P. waltonii, P. bella, P. poisonii|
|Classic spike inflorescence of P. vialii |
with diagnostic red calyces.
|Calyx, Tube & Bracts: |
P. munroi (L), P. longipetiolata (R)
|Leaf studies: P. blini (L), P. advena (R)|
|Glandular hairs secreting farina|
|Seed capsules: P. sikkimensis (L), P. calderiana (R)|
|P. allionii habitat|
I'm pleased to see any Primula images, but if you have time, a detailed study like that shown below of Primula boreiocalliantha is the pinnacle of excellence. Even common species need to be documented!
Field Checklist of images:
- Habitat – wide view showing the plants and their environment. Note aspect, moisture, base rock (granitic, limestone) and plant associations.
- Full plant – with measuring scale to show accurate height (or some indication of size, even if it is a finger or a hand.
- Leaf study – If permissible, remove a few leaves from several individuals by gently tugging downward from the stem so that the whole petiole remains with the leaf. Observe several plants and chose leaves showing variations. Image BOTH sides the leaves, side by side, with a scale. Take magnified images of any hairs, glands or pits on the leaf surfaces.
- Inflorescence study – Image the flowers from the back or side to show the calyx, bracts, tube, pedicels and upper scape. Note that pin and thrum forms may have different shaped tubes. Pull back a calyx lobe and document any farina inside.
- Flower study – Image the front of a pin flower and a thrum flower. If this characteristic is not obvious in the image, then cut a flower in half lengthwise and photograph it. If you suspect the species is homostylous, image several split flowers. If the flowers vary in color and size, and it is permissible, remove a few flowers and image them together with a scale to show relative variation. Tilt up flowers which hang down, to image the face of the flower.
- Farina – It can be hard to determine farina color from digital images due to color rendition problems and farina reflectivity. Observe and write down the farina color. Make sure your images show which parts have farina.
- Capsule study – If the plant is in seed or old seed capsules linger from previous years, image the seed capsule. Fresh capsules may be cut in half lengthwise to show the internal seed arrangement. Image the height of the scape with a measuring scale as the scape lengthens when the plant is in seed. If possible, show together the whole plant with old seed scape, and new flowering scape.
- Leaf rosette – Image the rosette (non-flowering plant is easiest) showing the new leaves unfurling in the center.
- Resting buds, bud scales - If the plant is imaged in early Spring, or late Fall, image the resting bud, documenting any farina present. If the plant is in flower, pull the leaves back to show any bud scales or a sheathing base.
- Root/stolon study – If permissible, remove a plant from the ground, and image the colors and structure of the roots. Image any stolons.
- Fragrance – note the fragrance of the flowers and/or roots and write it down.
Remember: Take as many Primula images as you can....and then take one more!