Gelidium pulchellum is a small to medium-sized red alga that forms bushy, erect, and often densely branched thalli. The fronds are cylindrical to slightly flattened, typically reaching heights of 2-10 cm. Branching is irregular or pinnate, and the branches are usually compressed and display a fine, delicate appearance. The surface is smooth, with a characteristic red to reddish-brown coloration that may vary depending on environmental factors.

In specimens collected from Buarcos (Figueira da Foz), the holdfast is typically well-developed, forming a discoid base that attaches firmly to rocky substrates. The thallus texture is cartilaginous and resilient, and reproductive structures (tetrasporangia) are often located in specialized branches, appearing as swollen areas. The alga thrives in intertidal zones, preferring well-illuminated and wave-exposed environments.