Primulaceae

The Primrose Family


Cyclamen persicum spp.	Anagallis arvensis spp.

The Primulaceae has about 28 genera (11 in the U.S.) and nearly 1,000 species in all. The family occurs throughout the temperate regions of the world, but is most abundant in the northern hemisphere. The plants are herbaceous and usually perennial while some are annual and are generally known for their showy flowers.

Click here for a distribution map of the Primulaceae in the U.S.A.

Vegetative Characters

Leaves usually opposite, basal or whorled, simple, exstipulate, sometimes with glandular hairs on leaves and stem
Plants generally herbacious and monoecious/synoecious
Flower symmetry radial or actinomorphic
Flowers subtended by bracts
Flowers maybe singular or in racemes, with cuplike or tubular corollas and calyx that have 5 well developed lobes
Perianth usually has distinct calyx and corolla
The 5 stamens are epiptetalous

Reproductive Characters

Plants reproduce throught pollination and are entomophilous
Androecium is opposite the petals
Gynoecium is syncarpous
Ovary is superior and hypogynous with free central placentation
Fruit is a non-fleshy, usually dehiscent capule
Seedling germination phanerocotylar

Diagnostic Characters

Calyx, corolla, androecium, and carpels in groups of 5 (5-merous)
Leaves without persistant basal meristem
Stem nodes are unilacunar
Carpels are often difficult to discern because the ovary has only one locule and free central placentation
Most species perennate by means of rhizomes (Primula) or tubers (Cyclamen)

Economic Importance/Fun Facts

Primarily used ornamentally
Some members of the family are poisonous (Cyclamen purpurascens) and a few have medicinal properties
Lysimachia provides a yellow dye
Flowers of Primula veris can be used to make home-made wine

Evolutionary Adaptations and Relationships

Primulaceae is a monophyletic group supported by morphological characteristics
The genera are divided into several tribes based on floral symmetry, ovary position, and aestivation of the corolla
The Primulaceae was once considered to be related to the Caryophyllaceae based on the nature of the gynoecium and other anatomical features.
Advances such as fusion of the corollaand reduction of androecium has since separated the Primulaceae from Caryophyllaceae two and related it to Ebenales

Glossary of Terms

Dehiscent - to split open
Entomophilous - pollination by insects
Meristem - region of tissue actively involved in cell division
Phanerocotylar - cotyledons emergent from seed and usually appearing above ground
Perenate - maintain a dormant state through the non-growing season
unilacunar - having only one gap or space enclosed by but free from veins

References and Links

http://plants.montara.com/ListPages/FamPages/Primula.htm
http://biodiversity.uno.edu/delta/angio/www/primulac.htm
http://www.arctic.uoguelph.ca/cpl/organisms/plants/Marine/primrose.htm
http://www.fornau.edu/azproject/Family/pri0.html
http://herbarium.usu.edu/families/primulaceae.html

Pictures


Primula vulgaris spp.	Trientalis borealis spp.


Primula japonica spp.	Anagallis arvensis spp.

For questions or feedback, contact: Kris Hamwi