The following helpful hints for plant identification come from the blog of Amy Hruska at the University of Hawai‘i at Mānoa.
. . . note the habitat your plant species of interest is in: is it in an urban setting (and likely horticultural) or is it in the forest? It is a good idea to take note of specific geographical information, such as known landmarks, trail names, or street names. Geographical information is always useful when identifying any plant or animal.
. . . do not remove the plant. In the age of cellphone photography, you can take pretty informative pictures if you know what you are photographing. This is both for your safety and the plant’s. WARNING: one photo of your mystery plant will probably rarely be enough. Here are the type of photos you will want to take:
1. Photograph the reproductive parts. Flowers are most helpful, followed by fruits.
2. Photograph the leaves. One leaf could be made up of many leaflets. Look for a bud where a leaf meets a branch or stem to determine if it has one or many leaflets. Knowing whether a leaf is made of one leaflet (simple) or many leaflets (compound) and the arrangement of leaflets is extremely helpful.
3. Photograph where leaves meet the stem. There are three main arrangements that leaves can have around a stem: alternate, opposite, and whorled.
4. Take a picture of the whole plant. This is important for knowing if this mystery plant is an herb, shrub, or tree. It also provides context for where the plant is growing, bark characteristics, etc.