Hyphae 2.3-9.1 µm in diameter. Dried weight of “+” strain (strain No. 018-4) 0.2027 gm and “_” strain (strain No. 018-1) 0.1927 gm after 5days’ culture. Sporangia oval, smooth, light brown, “+” strain 65-116 µm and “_” strain 28-70 µm. Sorangiospores dark brown, oval, with stiff bristle-like appendages on both ends, “+” strain 7-13 × 5-8 µm and “_” strain 6-10 × 6-7 µm. No conidia formation. Zygospoes 42-144 × 42-121 µm with density of 130/cm² on malt extract agar and 59-128 × 57-100 µm with density of 5-15/cm² on potato dextrose agar.
Specimens：
Taiwan, Hualien: Maowu seed farm, from soil under tree of Chamaecyparis formosensis , 03 Aug. 1985, culture strains 018, 018-1, 018-2, 018-3 and 018-4.
Habitat：
Saprobic in soil and on plant debris. On fading flowers of Colosia cristata L. and Luffa cylindrica (L.) Roem. and from many other woody plants, such as: Hibiscus rosaesinensis L., Hibiscus tiliaceus L., Wistaria sinensis (Sims.) Sweet, and from soil under trees of Hibiscus rosaesinensis L, Pyrus sp., Litchi chinensis Sonn., Hibiscus tiliaceus L. and Luffa cylindrical (L.) Roem from Taiwan.
Distribution：
Temperate to tropical regions, such as: America, Asia and only from Hualien areas of Taiwan.
References：
Wu, ML and Chien, CY. 1980; Wu, ML. 1975.
Provided：
M. L. Wu
Note：
This species only form sporangiospores. Furthermore, C. circinas can not form zygospores with Choanephora infundibulifera (Currey) Sacc., Choanephora conjuncta Couch and Choanephora cucurbitarum (Berk. & Rav.) Thaxter while the last three species can form zygospores with each other (Wu and Chien, 1980).
Phylum：Zygomycota >> Class： Zygomycetes >> Order： Mucorales 
BCRC Number：