University of Redlands

Common Name: Wilson Holly; "Wilsonii"

Scientific Name: Ilex altaclarensis

Family: Aquifoliaceae


Habit: The mature size of a Wilson Holly is approximately 180 - 300 inches tall and 180- 300 inches in width [7, 8, 10]. The shape and size of Holly is similar to that of a shrub and is medium in growing [5].


Figure 1. Wilson Holly pruned as a hedge.

Leaves: The leaves of Wilson Holly are compound and alternating [11]. The appearance of the leaves is green, shiny, dense and thick (Figure 2) [5, 10]. Additionally, the leaf blades are approximately 2-4 inches in length, stiff in toughness and have a leather-like texture [12]. The leaves also can have distinct yellow veins [11].leaves.jpg

Figure 2. Close-up of Wilson Holly leaves. Note that leaves may also have serrated, almost "poky" appearance.

Twigs & Bark: The bark of the tree is either a  gray or brown color. The texture of the bark is typically smooth (Figure 3) [10, 12].bark.jpg

Figure 3. Wilson Holly twigs.

Flowers & Fruit: The Wilson Holly is often pruned as a shrub (Figure 1) and in parts of the trees on the stem connecting the leaves are clusters of fruit (Figure 4) or also referred to as drupes  (i.e., resembles red berries) [5]. The Holly flowers in the spring and has male or female flowers [8, 12].berries.jpg

Figure 4. Wilson Holly fruit.

Where it’s from

Native range: The Wilson Holly is typically found in tropic, subtropic, and temperate regions throughout the world (5, 6]. This shrub is currently found in North America (along the coast of California all the way to British Columbia), where it occupies forest habitats [5]. The ancestral background of the Holly suggests that their ancestors were first found in Gondwana and Laurasia when the Earth’s mass separated [5]. Many Wilson Holly species were found in the Laurel forest [5]. This type of native habitat included qualities of high humidity, mild temperatures (Wilson Holly typically cannot withstand extremely cold temperatures), copious rainfall, and is located on slopes of tropical mountains (e.g. cloud forests) [5]. More specifically, some biotic factors in the Wilson Holly’s environment would include leaves on the forest floor, animals, and plants that are in the environment for the Wilson Hollys’ native habitat [5]. Whereas, some abiotic factors in the surroundings of the Wilson Holly would include water from rainfall, temperature, humidity, etc. for the Wilson Holly’s native habitat [5].

Ecological notes: Many of the Holly species are dioecious trees and require males and females both to be planted if fruits are desired [10]. A Holly berry consists of one seed in which the berries (red) are primarily dispersed by birds [4]. The Holly berries are eaten by wildlife (exception of deer) as fruits [10]. The Wilson Holly has adapted to many conditions due to its geographical locations across the country. The tree does well in both shade and sunlight [7]. Pests and diseases that affect the Wilson Holly are leaf miners (i.e., flies), mealybugs, scales, and sooty mold (a type of fungi) [10].

What we use it for

The Wilson Holly signifies economical importance for numerous reasons. For example, Wilson Holly is readily utilized in tree nurseries, holiday decor, and tea production [6]. Wilson Holly is widely used as a decorative piece because of its distinctive green leaves and red berries [6]. For that reason, Holly is used in many households during Christmas [6]. Additionally, Holly has also been utilized to construct furniture because the wood of the Holly is readily susceptible to the exposure of dye [13]. The Wilson Holly has illustrated its importance in many various ways from its ecological importance to traditions and cultural significance [6].


  1. American Holly. (n.d.). Retrieved from
  2. California-laurel (Umbellularia californica). (n.d.). Retrieved from
  3. Carter, K. (2017, November 21). The Best Place to Plant a Holly Tree. Retrieved from
  4. Do One Thing. (n.d.). Retrieved from
  5. Holly. (2019, March 08). Retrieved from
  6. Hu, C. Y. (1989, January 01). Holly ( Ilex spp.). Retrieved from
  7. Ilex a. Wilsonii. (n.d.). Retrieved from
  8. Ilex Altaclarensis 'Wilsonii'. (n.d.). Retrieved from
  9. Myers, V. R. (2019, March 10). If You Like Red and Green, Plant One of These Holly Trees and Shrubs. Retrieved from
  10. SelecTree: Tree Detail. (n.d.). Retrieved from
  11. Shaw, P. (1970, January 01). Trees of Santa Cruz County. Retrieved from
  12. USDA NRCS Plant Material Program (2012): American Holly Ilex opaca
  13. Wengert, G. (2016, September 28). Holly beautiful, but toxic. Retrieved from

* Images were taken by the biographer on the University of Redlands Campus behind Founders Hall *

Biographer: Shannon Rizik, BIOL 238: Evolution, Ecology, and Behavior, Spring 2019