Isidia numerous and dense to rather sparse, superficial (also marginal), concolorous with thallus or darker, squamiform (entire or a little incised) or some more teretiform, when young ± globular (often they grow out still remaining on thallus, forming small accessory lobules as in C. crispum, see Degelius 1954 pp. 38, 284).
Source: wiktionary