- Group 1Lycophytes, Monilophytes
- Group 2Gymnosperms
- Group 3Monocots
- Group 4Woody angiosperms with opposite or whorled leaves
- Group 5Woody angiosperms with alternate leaves
- Group 6Herbaceous angiosperms with inferior ovaries
- Group 7Herbaceous angiosperms with superior ovaries and zygomorphic flowers
- Group 8Herbaceous angiosperms with superior ovaries, actinomorphic flowers, and 2 or more distinct carpels
- Group 9Herbaceous angiosperms with superior ovaries, actinomorphic flowers, connate petals, and a solitary carpel or 2 or more connate carpels
- Group 10Herbaceous angiosperms with superior ovaries, actinomorphic flowers, distinct petals or the petals lacking, and 2 or more connate carpels
Individuals of Euphrasia are known to vary morphologically according to differences in nutrient supply, length of growing season, and height of surrounding vegetation (Downie and McNeill 1990). Therefore, some characters used to discriminate species of Euphrasia (e.g., internode length, number of nodes to first flower, number of branches), though generally useful, can show tremendous variation and should be confirmed through use of additional characters. Sell and Yeo (1970) noted specimens from the Plantae Exsiccatae Grayanae (number 62) that may be referable to Euphrasia ×aequalis Callen ( E. nemorosa ×E. tetraquetra) from Frenchville, ME. Reference: Sell and Yeo (1970).
1a. Bracts with subulate or bristle-tipped teeth [Figs. 751,752]; corolla 5–8 mm long
1b. Bracts with obtuse to acute teeth; corolla 2.5–5 (–7.5) mm long
5b. Calyx lobes acute at the apex and ± straight; stems usually with 1–4 (–5) branches from the middle and upper (rarely the lower) nodes or rarely simple; flowering beginning from the 3rd to the 8th node (rarely as high as the 10th node)
Show photos of: Each photo represents one species in this genus.