The bracted twistflower
(Streptanthus bracteatus)


Austin's vanishing wildflower



Going, going, ....?

Natural history

Life cycle:  Seeds germinate in the fall.  Plants grow as rosettes (see picture at right above) during the winter.  They flower in April or May, sending up flowering stalks 1-4 ft tall with 4-petaled flowers.  In the summer, the seeds in long pods ripen and then the adult plants die.   Seeds can remain dormant in the soil for years.

Habitat:  Rocky hillsides and slopes.  It is usually found growing under shrubs, but it may not need shade; its present association with shrubs might be because deer have eaten the plants in the open.

The situation now

  • There are only a few small populations left in Austin.

  • All but three of these are on private land that is now being developed or is likely to be developed.  Some of the populations on public land are declining.

  • There are only a few known populations of this species elsewhere in Texas.  There are none in any other state.

Why is the bracted twistflower vanishing from Austin?

Development: The bracted twistflower only lives on some of the hillsides and hilltops on the western side of the city - where people like to live, too.  Houses now occupy sites where it used to live.

Deer: Deer think it's tasty - and there are many more deer now than there used to be.

???: There are probably additional reasons for its rarity.  Suspicion currently rests on recent increases in cedar density.  The bracted twistflower may have some special soil requirements, too.

Can anything be done to save the bracted twistflower?

Two possible strategies to save the bracted twistflower

  • Fencing to keep deer away from the remaining plants.

  • Establishing new populations in suitable sites that are protected from development.  The first step in this process will have to be discovering how to do this, since previous attempts have not been successful.

[Why isn't buying the land where bracted twistflowers grow in this list? Because it would be very costly.]

For more information, contact

Dr. Tim Schumann, Biologist, US Fish and Wildlife Service Partners for Wildlife Program, phone 512-490-0057, email

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