Hyssop Spurge

Euphorbia hyssopifolia

Description 3

Plants robust, ascending to erect annuals; hairy or glabrous; may attain a height of over 30 cm tall; not typically branching much at the base. Stems glabrous (with scattered pilose hairs in other areas); largest internodes may get up to 3 mm in diameter. Stipules fused on both sides of the stem except near the apex where they separate; usually serrated. Leaves oblong-lanceolate (to linear-lanceolate SW of the Llano) and usually slightly crescent shaped; leaves may have a silvery line or red “splotch” in the center along the midvein; most leaves 1.5-2 cm long and longer. Cyathia about 1 mm across. Appendages mostly entire. Styles long and slender. Fruits glabrous. Seeds with 3 transverse ridges; mostly dark grey in color.

Habitat and Distrabution 3

I have found this species growing as a weed in garden beds and lawns in Midland and Seminole. Also, it is a common weed in the pots of plants being sold in both Midland and Lubbock. This species was likely introduced to the region through cultivated plants.

Comments 3

Many people have confused E. hyssopifolia, E. hypericifolia, and E. nutans. Euphorbia nutans has not been observed on the Llano yet. Euphorbia hypericifolia has been observed once in Lubbock. All three species can be distinguished using the following characters:

Euphorbia hyssopifolia: Stems glabrous or with pilose hairs; stipules shorter than 1 mm erect; cyathia solitary, at most in dense leafy inflorescences.
Euphorbia hypericifolia: Stems always glabrous; stipules longer than 1 mm spreading away from the stem; cyathia in dense leafless inflorescences (a single solitary cyathium is usually present at the node before the nodes holding the dense inflorescences).
Euphorbia nutans: Stems always with some short crinkled hairs; stipules shorter than 1 mm erect; cyathia solitary, at most in dense leafy inflorescences.

Sources and Credits

  1. (c) Nathan Taylor, all rights reserved, uploaded by Nathan Taylor
  2. (c) Nathan Taylor, some rights reserved (CC BY-NC), uploaded by Nathan Taylor
  3. (c) Nathan Taylor, some rights reserved (CC BY-SA)

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