Long-stalk holly features alternate, simple leaves measuring 1 to 3 inches (2.5 to 7.6 cm) in length. The leaves are dark green and may develop a yellowish-green cast in harsh winter conditions. They exhibit a narrow, entire (untoothed) margin and possess a pear-like shape. The texture is smooth, and the leaves show prominent midrib and secondary veins, which are typical of the genus. These characteristics are essential for identifying long-stalk holly in various environments.

The flowers of long-stalk holly are understated yet distinctive. Female flowers are white and typically appear solitary on the current season's growth. They measure approximately 0.2 inches (5 mm) in diameter. In contrast, the male flowers are grouped in clusters, also small and white, creating a visually subtle but scientifically fascinating display. These flowers generally bloom in the spring, emitting no discernible scent. Their simple arrangement and diminutive size make them notable in their subtlety.

The stem of long-stalk holly is slender and glabrous, presenting a smooth and somewhat flattened texture. Its coloration ranges from light green to reddish-brown, offering a subtle shine in sunlight. Measuring up to approximately 1 inch (2.5 cm) in diameter, the stem maintains a consistent thinness throughout its length. Branching is sparse but evenly distributed along the stem, providing a balanced structural appearance. These features make it distinguishable among similar species.

The fruit of long-stalk holly is a vibrant, bright red berry, approximately 1/4 inch (6 mm) in diameter. These berries are borne on relatively long stalks, ranging from 1 to 2 inches (25 to 50 mm) in length, which become particularly conspicuous in fall and winter. The fruit's glossy surface and striking color provide a distinct visual against the foliage, making them quite noticeable. Typically, these berries persist on the plant through the colder months, offering a pop of color in predominantly dormant landscapes.