Flowers:

Ilex mucronata, mountain holly, plants are almost always dioecious: individual plants have only male flowers or female flowers. Occasionally, a flower with both male and female parts occur although it is not certain that both are fertile. The only way to distinguish between male and female plants is by their flowers or if they have fruits.

The individual flowers are inconspicuous about an 1/8 inches across. The flowers are white to yellowish white. They grow singly on long stalks that form at the leaf axils along new branches. The flower stalks are thin, hairless, and 1 - 2 inches long. The flower petals are narrow, linear and alternate with the stamens/staminodes. The sepals are minute. The flowers have 4-5 petals and 4-5 stamens/staminodes. The flowers appear with the leaves in spring.

Female (pistillate) flowers: Fertile pistil, sterile stamens (staminodes)  

Male (staminate) flowers: Fertile stamens, sterile pistil (pistillode) 

Fruit:

The mature fruits are bright red round berries that are 1/4 to 1/3 inches in diameter. They mature in late summer and persist through the winter.

Leaves:

Ilex mucronata, mountain holly, leaves are simple and alternate. The leaves are very crowded at the tips and appear to be whorled. They are 1 to 2 inches long with variable shapes: oblong (sort of straight sides, rectangular)-elliptic (widest in the middle) to obovate (widest at the tip end). Leaf margins are basically entire, smooth, but with a occasional minute tooth. The tip is rounded to an occasional sharp tooth (mucronate). The leaves are hairless.

New twigs are reddish-purplish brown with white lenticels (pores). The leaf stalks are reddish brown also. Older twigs are grayish brown.

Below, the first 2 photos, the leaves are oblong-elliptic with a sharp tooth at the tip. The last photo shows the leaf back sides and the leaves are obovate. Also, the reddish-brown coloration and lenticels can be seen.

Ilex mucronata, mountain holly, is a deciduous shrub that grows to 10 ft. The stems are upright and multiple from the base. It grows mainly in wet habitats - moist woods, edges of bogs and swamps.

In NJ, mountain holly, Ilex mucronata is S3 (Vulnerable). In iNaturalist there are only 6 observations mainly up north (2025). We observed them in Sussex County also.

The common name - mountain holly (Ilex mucronata) - is confusing because there is a holly - Ilex montana - and its common name is mountain winterberry or mountain holly!