Yew

Basic Information
Tree ID: 
38
Family: 
Taxaceae
Genus and species: 
Taxus x media
Description: 
This 1.78m specimen of Taxus x media is an evergreen with needle-like dark green foliage that sways in the university president's front yard on Hillhouse Avenue. Poisonous if ingested, it is a hardy, spreading conifer that can tolerate a wide range of soil and sun conditions, as well as pruning. This is a hybrid of Taxus cuspidata and Taxus baccata that was first bred in the early 1900s. Although it is slow-growing, it can grow to roughly 5 feet tall by 10 feet wide if left unpruned.
Surveyors: 
Emma Graham and Jenny Nguyen
Location
Area: 
Hillhouse
Collected Data
Tree shape: 
Varied (Can be pruned to many forms)
Date of tree entry: 
03/03/2016
Height: 
1.78 m
The tree is not tall enough to measure DBH, so this is a measure of the base of the tree
There are too many multiple trunks to accurately measure the DBH, so this is just an estimate
Bark
Taxus x media has bark that has variations in color and flakes with age. The flaky bark on the curved portions of the trunks is reddish-brown, sometimes with shades of purple. The bark on the branches gradually becomes lighter closer to the terminal branches, where the bark is green.
Twigs & branches
A spreading evergreen, Taxus x media has numerous branches and twigs of varying diameters. The branches and twigs exhibit pronounced twisting and bending, and vary in color. First-year stems are green, gradually progress to a tan-green color in their second year, then become brownish-red with hints of purple in later years.
Foilage
Taxus x media has leaves that are needle-like in appearance. They line the smallest stems and follow a feather-like shape that tapers towards the base of each stem in a pectinate arrangement. The leaves are arranged in paired rows along each side of the stems. The emerging evergreen needles are first light green but transition to dark green. They are dull shiny, up to 4cm long, and flattened. During winter, exposure to dry winds may cause "winter burn" that turns the foliage brown.
Reproductive Structures
Taxus x media are dioecious (male and female cones are in separate plants) - the staminate cones are small, off-white in color, and develop in bunches, whereas the pistillate cones are small and grow solitarily on green stalks. Conifer species do not produce fruit, instead, Taxus x media produces a fleshy, red aril which surrounds each female cone. The aril is not a berry, but is a highly modified seed cone scale. The arils are usually hidden among the foliage until the fruit becomes visible hanging from stems in early Fall. Each aril has a square opening at the bottom of its flesh that contains a brown cone. These arils are non-toxic, and are consumed by various types of birds.
Seasons
  • Late Winter
  • Early Spring
  • Late Spring
  • Mid Summer
  • Early Fall: While not taken from the same angle as the others, this photo clearly shows the red arils in the female tree that emerge in late Summer to early Fall.
Research
Habitat: 
Taxus x media can tolerate all types of soil except excessively wet soil, which drowns the roots. It can grow in both full shade and full sun. As the hybrid between Taxus cuspidata (Japnese Yew - from Japan) and Taxus baccata (English Yew - from England), it has the ornamentatal excellence of the English Yew and the hardiness of the Japanese Yew. It is found in a wide range of Northern climates.
Origin, history, and uses: 

Taxus x media was created by the Massachusetts based horticulturist T.D Hatfield in the early 1900s. All yew trees are poisonous to humans as well as many animals. This was discovered when people noticed that many livestock that grazed on yew trees died. As a result, these trees were confined to church yards and areas away from livestock. Everything except for the fleshy portion of the fruits of all yew trees contain a toxin named Taxine, which is poisonous when ingested.

One use for yew trees is in the creation of cancer drugs. One American species contains Taxol, which is a compound that has been successfully used in regimes to to treat cancer. The compound has been chemically extracted and purified from the bark of Taxus brevifolia, more commonly known as the western yew.

Another use for yew trees is in landscaping because it is a fairly low and dense spreading evergreen that is durable and versatile. It tolerates a wide range of conditions and can be sheared, so they are often pruned into rectangles for hedges.

Phenology: 
As a hybrid plant, it is not reproducable from its seeds. Instead, to generate taxus x media, a 5-8cm terminal branch of the hybrid must be planted. When planted in the Fall, it often takes 18 months to germinate. Seeds germinate in the Fall, and male flowers release their pollen in March. The male flowers bloom in late Spring to early Fall. The red, berry-like fruits of the female plant are visible for a short time in late Spring, when they are consumed by birds and spread to neighboring areas.
References: 
“Dense Spreading Yew.” Monrovia. Monrovia, n.d. Web. 27 Apr. 2016. <http://www.monrovia.com/plant-catalog/plants/2145/dense-spreading-yew/>.
“Greenleaf Nursery Company.” Taxus X Media ‘Densiformis’ DENSIFORMIS YEW from Greenleaf Nursery. Greenleaf Nursery Company, n.d. Web. 27 Apr. 2016. <http://www.greenleafnursery.com/index.cfm/fuseaction/plants.plantDetail/….
“Taxus × Media ‘Densiformis’ - Plant Finder.” Taxus × Media ‘Densiformis’ - Plant Finder. Missouri Botanical Garden, n.d. Web. 27 Apr. 2016. <http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.as….
“Taxus X Media - Rehder.” Plants for a Future. N.p., n.d. Web. <http://www.pfaf.org/user/Plant.aspx?LatinName=Taxus+x+media>.
“Taxus X Media.” Taxus X Media. Ohio State Universit, n.d. Web. <http://www.pfaf.org/user/Plant.aspx?LatinName=Taxus+x+media>.
More
Other information of interest: 

Fun fact for Harry Potter fans: Voldemort’s wand was made of wood from the yew tree!

Media and Arts
Yew Tree Song by Emma and Jenny