Zygophyllaceae
Notes for Plant Taxonomy (Bio 3400) at Utah State University
Links: habit, flowers, reproductive characteristics

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Larrea divaricata ssp. tridentata

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Fagonia laevis

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Zygophyllum auranticum 

 

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Larrea divaricata

 

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Larrea divaricata
The Zygophyllaceae is best known in Utah for Tribulus terrestris, the aptly named puncture vine,  and Larrea divaricata or Creosote Bush that marks the Mohave desert region of Utah in Washington County.  The name of family means 'twinned leaf' and can serve to remind you that most of its members have evenly pinnately compound leaves.

Members of the Zygophyllaceae include trees, shrubs, and herbs that are often jointed at the nodes.  The leaves are usually opposite, 2-ranked, and evenly pinnately compound.  They usually have stipules and are often resinous. 

The flowers are bisexual, radially symmetric, and have 5, more or less distinct, sepals and 5 distinct petals. 

There are 10-15 stamens, often with a basal gland, and 2-5 connate carpels. The ovary is superior, the stigma punctate.  Fruit is a capsule, rather an unpleasantly spiny capsule in the case of puncture vine.

The family has a few members of note.  Lignum vitae, which refers to its  very hard, heavy wood, belongs here  and both Larrea and Tribulus are apparently used as ornamentals, but not in my back yard.