A medium to large species. In open habitats S. inundatum appears golden orangebrown, while in shade it is yellow-green or all green. The capitulum is somewhat stellate, with outer branches straight or curved only at the tip. The branch leaves are spreading, not appressed to the branch, giving the capitulum and upper branches a spiky appearance, hence, despite the common name, not looking like cows- horns. On the lower part of the branches, some leaves are asymmetrical, the upper half turned to one side when viewed from above. Fascicles usually have 5 or more branches, all with well-developed leaves. Typically there are 2 strongly divergent branches, 2 deflexed to pendent, and 1 more or less hanging vertically down the stem. The stem is dark brown to almost black, or green in shaded forms. Stem leaves are nearly always more or less triangular. The whole shoot is about 10-15 mm wide and parallel-sided. Capsules are occasional.