Tracking Townsendia
Townsendia, or Easter daisy, are one of the first plants to bloom in the foothills. Like their common name suggests, you will typically begin seeing them bloom around Easter. Although the weather can be quite cold this time of year, Easter daisy is adapted to withstand freezing conditions and blankets of snow. These plants form low mounds close to the ground, a successful strategy that helps to maximize heat retention during colder periods.
As a member of the Compositae (Asteraceae), or aster family, these “flowers” are not all that they appear at first glance. Indeed, what looks like a single flower is actually a composite of many flowers arranged in an inflorescence called a head. Inside of this head, there are even two different types of flowers present – ray flowers, which are petal-like, on the outer periphery of the head, and disk flowers in the center. These heads are nested amongst a rosette of leaves, protecting them from potentially cold conditions.
There are two species of Townsendia in the metro area that you might see flowering – T. exscapa and T. hookeri. These two species can be very difficult to tell apart – the main difference being that T. exscapa has larger heads with disk flowers over 6.5 mm while T. hookeri has smaller heads with disk flowers under 6 mm in length.
Documenting the flowering period of species such as these can ultimately aid our understanding of plant responses to a warming climate. By comparing observations, in combination with natural history collections dating back over 100 years, we can better understand how seasonal patterns are changing, and even make predictions for the future.
See if you can locate some Easter daisies and help Denver Botanic Gardens document their flowering period by photographing as many plants as possible in the month of March. Post your findings to iNaturalist so they will automatically be added to the Denver EcoFlora Project.
@astrobirder
T. hookeri
@christian_nunes
T. hookeri
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