Primrose Family

Henderson’s Shooting Star © TCorelli

Primulaceae (prim-u-LA-see-ee)

Iconic Features

  • Simple leaves, often in basal rosettes
  • Flowers in umbels, often from a scape
  • Flower parts usually in fives
  • Stamens aligned with petals

Description (Jepson)

  • Eudicotyledons (eudicots) – a major lineage of flowering plants including most plants traditionally described as dicots and generally characterized by
    • 2 seed leaves (dicotyledon)
    • Netted (reticulate) leaf venation
    • Flower parts in fours and fives
    • Pollen grains with 3 pores (tricolpate)
    • Vascular bundles in stem arranged in a ring
    • Taproot system
  • Annual or perennial herbs or slightly woody plants
  • Leaves
    • Simple (not divided into leaflets)
    • Generally in a basal rosette; or may be opposite (2 leaves at each junction with stem) or whorled (3 or more leaves/flowers at each junction with stem)
    • Lack stipules (pair of leaf-like structures at the base of the leaf stalk)
  • Flowers
    • Inflorescence (flower arrangement) an umbel (a spoke-like flower cluster with stalks radiating from a single point)
      • Often on a scape (a leafless stem rising from ground level)
    • Bisexual, radially-symmetrical flowers
    • Flower parts usually in fives
    • Stamens (male flower parts) aligned in the middle of each petal
    • Ovary superior (above the attachment of other flower parts)
  • Fruit a capsule (a dry, multi-chambered fruit that splits open at maturity)


  • Approximately 600 species in the northern hemisphere
    • Includes shooting stars and the common garden plants primrose and cyclamen
  • Some plants in this family (e.g. shooting stars) are pollinated most effectively by sonication or “buzz pollination”
    • Flowers have specialized “poricidal,” tube-shaped anthers containing firmly-attached pollen and having, unlike most anthers, small openings, like a salt shaker, which regulate the dispersal of pollen
    • Only bumblebees, along with a few other native bees, can release this pollen by grasping the flower with their legs or mouthparts and vibrating their flight muscles without moving their wings (See video Buzz Pollination)
    • Vibrating bees may generate forces 50x that of gravity–5x what fighter jet pilots experience (U. of Stirling 2020), causing pollen to “blast out” of the anthers (Zimmer 2013)
    • Buzz-pollinating bees make a distinctive, middle-C “raspberry” sound, which is higher pitched than the buzz of flight (Rosenthal 2008)
    • Only about 9% of the world’s flowers are buzz pollinated (Buchmann 1985)
    • A number of important agricultural crops, such as tomatoes and potatoes, require buzz pollination
    • Poricidal anthers have evolved several times in disparate plant families, an example of convergent evolution (de Luca and Vellejo-Marin 2013)
  • Scientific name from the included genus Primula, from the Medieval Latin phrase prīmula vēris, “little first one of the spring,” referring to the plants’ early flowering
  • Common name from Medieval Latin prīma rosa, “first rose”
  • Distinct from the similarly-named Evening Primrose Family (Onagraceae), which includes clarkias and sun cups
  • Represented by 2 species at Edgewood

See General References

Specific References

Buchmann, S.L. 1985. Bees use vibration to aid pollen collection from non-poricidal flowers. Journal of the Kansas Entomological Society 58: 517-525. JSTOR.

de Luca, P.A. and M. Vellejo-Marin. 2013. What’s the “buzz” about? The ecology and evolutionary significance of buzz pollination. Current Opinion in Plant Biology 16: 429-435.

University of Stirling. 2020, Jul. 29. Bees’ buzz is more powerful for pollination, than for defense or flight. ScienceDaily.

Zimmer, C. 2013, Jul. 11. Unraveling the pollinating secrets of a bee’s buzz. New York Times.

Browse Some Edgewood Plants in this Family