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Family: Zygophyllaceae

Kingdom: Plantae Rank: Family Parent: Sapindales Status: Valid

Common Names:

  • CALTROP FAMILY - English, United States of America

Morphological Description

Family Recognition in the Field: Opposite, even-pinnately compound leaves, the entire, asymmetrically-based leaflets in 3-8 pairs; fruit a small schizocarp or a capsule.

Diagnosis: Ours pubescent to pilose, prostrate to decumbent annuals or evergreen shrubs or small trees; leaves opposite or crowded in fascicles at the nodes, even-pinnately compound; leaflets 3-8 pairs, with asymmetrical bases, entire, folding together at night or in bad weather or in Guajacum sometimes in heat of day; stipules linear-lanceolate or subulate; flowers solitary or in small clusters, pedunculate; sepals 5; petals 5, yellow or orange or in Guajacum blue to purple, pink, or white; stamens 10 (bristles on ovary sometimes resemble additional filaments); ovary superior, 2-5-carpellate; fruit a schizocarp, 2(-3-4) or 5- or 10-lobed or -loculed, separating at maturity into 5 or 10 sections (mericarps) or a septicidal capsule.


Notes: A small (285 species in 27 genera) mostly tropical and warm, especially dry area family of mainly shrubs, herbs, and a few trees; alkaloids or mustard-oils are sometimes present. The family includes Gaujacum officinale L. and Guajacum sanctum L. (both referred to as LIGNUM VITAE), producing some of the world's hardest wood and a medicinal resin. The family also includes the abundant aromatic Larrea tridentata (Sess. & Moc. ex DC.) Coville (CREOSOTE-BUSH) of w TX. Family name from Zygophyllum, a genus of 80 species native from the Mediterranean region to c Asia, s Africa, and Australia, often in desert or arid regions. (Greek: zygo, yoke, and phyllon, leaf, in reference to the paired leaflets) (subclass Rosidae).