Colonies on YpSs (Yeast Starch Agar: Yeast extract 4g, Soluble starch 15g, K2HPO4 1g, MgSO4. 7H2O 0.5g Agar 20g, Dist. H2O 1000 ml) grow very rapidly and attain full plate in 6 days at 40°C. Mostly prostrate mycelia, grow radiately, undulate zonation. By spores maturation, the color at first White, Mouse Gray, Deep Mouse Gray and Dark Mouse Gray; reverse Colonial Buff, Dark Heliotropes-Slate. (The color based on Ridgway, 1912)
Conidia single or a short chain of 2-3 spores, with stalk or without. Stalk hyaline, unbranched, 1.7-4.0 × 3.4-20.0 μm. Occasionally intercalary spores were founded on aerial and substrate mycelia, mostly on substrate mycelia. Spores smooth, mostly globose or fusiform (7.5-12 × 11.4-20 μm), pale yellow at first, becoming brown then turning to dark brown with age. The falling spores possess apicula on the area of connection with stalk.
Specimens：
Corn field soils (low land) at Che-Chemg Hsiang, Pingtung County, Taiwan, 10.VIII.1986, K-Y Chen 8608-37.
Habitat：
Field soils
Distribution：
Australian, California, Japan, Saudi Arabia, Taiwan
References：
Chen, KY and Chen, ZC. 1995; Cooney, DG and Emerson, R. 1964.
Provided：
K. Y. Chen
Note：
Temperature tests: The optimum temperature of growth is between 30°C and 50°C.
Most of Humicola species were isolated from compost, i.e., mushroom compost, horse manure, waste compost, etc. In contrast, our isolates were isolated from corn field soils. Both H. insolens and H. griseus var. thermoidea are a similar taxon. However, Cooney and Emerson(1964) and Fergus(1964) made distinction of both taxa by following characters (1) distribiution of chlamydospores: H. insolens produces abundant chlamydospores on both aerial and substrate mycelia, and H. grisea var. thermoidea, mostly on substrate mycelia; (2) number of chlamydospores: H. insolens produce 15-30 spores, in contrast H. grisea var. thermoidea produced 2-4 spores in a short chain (Cooney and Emerson, 1964; Ferfus, 1964; Ellis,1982). But Awao and Otsuka(1974) suggested H. insolens was probably a synonym of H. grisea var. thermoidea . The obvious morphological and ultrastructural similarity be-tween H. insolens and H. grisea var. thermoidea was observed by Ellis (1982). But Bertoldi et al. (1973) found H. grisea var. thermoidea have difference in GC content of up to 13％. Ellis (1982) changed H. grisra var. thermoidea to H. insolens var. thermoidea. In this study, Ellis’ treatment was followed.
Phylum：Anamorphic fungi >> Class： Anamorphic fungi >> Order： Anamorphic fungi 
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