Diversity: 22 genera and about 1,000 species of mostly perennial herbs with a few suffrutescent taxa.
Distribution: Centered in cool, north-temperate parts of the World with some extension southward at high elevations. We have 6 genera in the Texas flora with 11 species.
The California flora includes 9 genera and about 22 species of the Primulaceae and an overview of floral variation is available from the CalPhotos website. This opens with photos of the Scarlet Pimpernel (Anagallis arvensis) that has blue flowers. While corolla color of this introduced (from northern Europe) weed is normally, as indicated by the local name, scarlet to salmon, plants producing blue flowers are not uncommon in either California or Texas. The difference between blue and reddish corolla pigmention has a relatively simple genetic foundation and, as a result, the blue form of Anagallis arvensis is sometimes not recogized as a formal element of the classification system or often treated at the lowest level - forma, i.e., A. arvensis L. f. caerulea (Schreb.) Baumg.
As the name indicates, the plant was first named by Linnaeus and the parenthetical authority points to some history with regard to the 'caerulea' name that has involved 'Schred.' and 'Baumg.' The Harvard University Herbarium provides an Authors Database online that allows entry of the abbreviated name as a query to determine the full author's name and other info. This indicates that:
Schred. = Johann Christian Daniel von Schreber (1739
Baumg. = Johann Christian Gottlob Baumgarten (1765-1845)
More information on the Primulaceae