Desert race for life

The record for the oldest living plant goes to a Great Basin Bristlecone Pine (Pinus longaeva), which lived to be over 5000 years old. Quite impressive, but all it’s managed to do is not die. Boring! What about the plants living life in the fast lane?

If you sift through the dusty soils of the North American deserts you’ll find a secret garden waiting to leap into bloom. Each square metre contains tens or even hundreds of thousands of tiny seeds all hoping for one thing: rain.

These are the desert ephemerals, the Ferraris of the plant kingdom that can complete their life cycle from seed to seed in just a few short days or weeks.


Chinchweed - Pectis papposa

Chinchweed flowers brighten up the desert. Image credit: Stan Shebs

Cinchweed (Pectis papposa) can germinate, grow and set seed in just four to six weeks, covering the desert with beautiful yellow flowers after the summer rains. Its fragrant leaves and seeds were used by native Americans as a condiment for cooking.


Desert ephemerals are a type of annual plant, which grow, reproduce and die back within a single growing season. Seeds of annuals are dispersed and remain dormant in the earth, poised to take advantage of the perfect growing conditions.

Instead of being slow growing like many desert plants, ephemerals spring up during the short wet season to dominate other species. They are not well adapted to dry conditions, so instead of wasting time growing into huge plants they stay small and reproduce rapidly to produce seeds.

Seeds are a lot more resistant to long periods of drought because they have an ultra slow metabolism, so don’t require water. The dry conditions in deserts prevent rotting, so the seeds may remain in the soil for many years if necessary.


This super cute tiny grass is called six-weeks grama (Bouteloua barbata). Its short stature helps it to quickly flower and produce hundreds of lightweight seeds.

Boutelouabarbata

Teeny tiny flowers of six-weeks grama. Image credit: Matt Lavin

Boutelouabarbataplant

Speedy growth means short stature. Image credit: Jacopo Werther 

 

 

 

 

 

 

 

 

 


Desert ephemerals may not stick around, but they have several important roles to play even after they’re dead. The dry plant material covers a lot of ground, preventing the arid soil from being too badly eroded by the wind. Their seeds are a nutritious lifeline for rodents and insects living in the harsh desert environment long after they’re dead. Not bad for a few weeks work.


 The real winner of the speedy life cycle contest has to be Plantago ovata, the desert Indianwheat. It races through life in just 2-3 weeks!

Plantagoovata

Plantago ovata, possibly the speediest flowering plant. Image credit: Stan Shebs


So there you have it. Desert ephemerals win the incredible plant race for life, often providing a stunning floral display in an otherwise pretty barren landscape.

Want to know more? Let Sir David Attenborough show you the desert in bloom.

 

P.S. If you’re into plant science, you’ve probably heard of another desert ephemeral without knowing it; Arabidopsis thaliana, the model plant!

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