|Photo by Shirley Denton (Copyrighted, use by photographer’s permission only), Nature Photography by Shirley Denton|
|Division:||Magnoliophyta - Flowering plants|
|Class:||Magnoliopsida – Dicotyledons|
| Sida acuta|
|Natural range of Sida acuta from USDA NRCS Plants Database.|
Common names: Common wireweed, Broomweed
Synonyms: Sida carpinifolia Linnaeus f.; S. ulmifolia P. Miller
The specific epithet means sharpened to a point, in reference to the tip of the leaves.
Erect branched suffrutex up to 1 meter tall, rarely taller. Green stems, mostly hairless to stellate-hairy, particularly on younger parts. Leaves more or less narrowly lanceolate, 2-6(10) cm long; apex acute; base obtuse to rounded, hairless to sparsely stellate-hairy; margin regularly serrate; petiole c. 2.5 mm, pubescent. Stipules linear, usually longer than the petiole. Flowers axillary, solitary or 2 together. Calyx 6-8 mm long, somewhat angular, saucer-shaped, hairless, lobed to the middle; petals as long as calyx, yellow. Mericarps 5-6, c. 4 mm long, birostrate, grooved between the awns.
Distributed from South Carolina throughout Florida and west to Mississippi.
Flowers are borne singly or in small clusters in the leaf forks on short stalks. Flowers have 5 yellow petals and 5 sepals.
Seeds have two sharp awns that easily attach to animals and clothing.
Seed bank and germination
Seeds have an innate dormancy period, the embryo requiring a post-ripening period of 1 to 3 months at high temperatures before germinating.
The following Hymenoptera families and species were observed visiting flowers of Sida acuta at Archbold Biological Station: 
Halictidae: Augochlorella gratiosa
Conservation and management
In Northern Australia, it is considered an invasive species. It dominateds improved pastures, disturbed areas, and contaminates agricultural produce.
Cultivation and restoration
References and notes
- []Eat the Weeds. Accessed: March 14, 2016
- []Encyclopedia of Life. Accessed: March 15, 2016
- Flanagan, G. J., L. A. Hills, et al. (2000). "The successful bioloical control of spinyhead Sida, Sida acuta [Malvaceae], by Calligrapha pantherina in Australia's Northern Territory." Proceedings of the X International Symposium on Biological Control of Weeds
- []Accessed: March 15, 2016
- Lonsdale, W. M., G. Farrell, et al. (1995). "Biological Control of a Tropical Weed: A Population Model and Experiment for Sida acuta." Journal of Applied Ecology 32(2): 391-399.
- Deyrup, M.A. and N.D. 2015. Database of observations of Hymenoptera visitations to flowers of plants on Archbold Biological Station, Florida, USA.