Taxus cuspidata (Japanese yew)

Taxus cuspidata is a fairly common yew in North America. Although it is commonly grown as a shrub or hedge in many landscapes, it is very commonly used as a bonsai in oriental countries. It can grow up to 50 feet in its native, oriental environment, but it rarely exceeds 30 feet in the United States. Yews are dioecious, with yellowish cone-like flowers emerging in March or April on male plants and seeds encased in red arils, once mature, in late autumn (October) on female trees. All yews have poisonous qualities, and consumption is heavily advised against. Yews should not be grown in areas where horses are present, as the horses which eat yew foliage are often killed by the toxins.
Yews are particularly interesting to me, for probably two reasons. Foremost, there are tons of them grown around where I live, mostly in shrub form. I have been blessed to have a moderately sized female tree in my backyard, which I have studied last autumn. Secondly, the morphology of yews is particularly peculiar. They evolved, at least supposedly, alongside conifers and evolved many similar traits to modern day conifers. The differences in foliage, branching patterns, and methods of reproduction show their fairly vast differences, but you would still think that they evolved with conifers, not alongside them. They are still relatively closely related to conifers, although their contrasting qualities have led to multiple theories of their evolution to arise.

Taxus cuspidata (Japanese yew)
Deciduous: no
Hardiness Zones: 4-7
Height: These grow 3-7 meters (10-25 feet) in North America; Japanese Yews grow up to 50 feet in their native habitat (Japan, Korea, China).
Diameter: 5-10 feet
Growth Rate: slow to moderate
Age: Maximum height occurs when the tree is 20 years old.
Root System: Minimum root system depth is 16 inches when mature.
Family: Taxaceae
Subspecies: ‘Capitata’, ‘Emerald Spreader’, ‘Dwarf Bright Gold’, ‘Aurescens’, ‘Columnaris’, ‘Expansa’, ‘Nana’

Tolerates: rabbits, drought, heavy shade, urban air conditions, pruning (especially in early spring)
Problems (major): Wet conditions are extremely detrimental and often lead to root rot.
Problems (minor): Winter winds can be harmful to the plant’s overall health and can lead to ‘winter burn’. Weevils, mealybugs, and scale are potential problems for certain areas.
Poisonous: Every part of the plant, except the red fleshy arils, is poisonous. Yews are not meant to be grown in areas where horses are present,

Soil requirements: Moist, sandy loams work best. 5.3-7.8 pH is optimal.
Air Requirements: Japanese yews don’t mind urban conditions.
Watering requirement: Medium amounts of water are preferred.
Sun requirement: Full-sun is fine; part-shade is preferred.

Needles: Form in flat sprays, two-sided (dark green on top, light green below)
Cones (male): none?
Cones (female): none?
Leaves: none
Flowers: Male ‘flowers’ are small, yellowish-white, and release pollen in early spring (March-April) when shaken.
Fruits: The female ‘cones’ are hidden inside of an aril, a fleshy, berry-like structure. The seeds are green when immature and exposed. As the cones age from early to late autumn, the aril forms. The aril changes from light green to yellow to orange to red, once finally mature.
Seeds require stratification: Yes, unfortunately, seeds require two periods of cold (with an intermediate, warmer time period). Sadly, this makes germination very lengthy and growing yews from seed takes an incredible amount of patience.
Monoecious or Dioecious: Dioecious, male and female ‘cones’ grow on separate trees.

Notable characteristics:
Yews, in general, do not exhibit monopodial branching. Basically, this means that yews do not have one primary trunk. Yews grow several trunks branching off in several directions, creating a (usually) pyramidal shape. The

Uses:
Grown mostly as hedges in groups. Mature trees, not shrub-shaped, in the American Midwest is rare. Japanese yews are commonly used as bonsai in oriental countries. Propogation is commonly done by hardwood cuttings due to the extensive stratification time.

Sources used:

Taxus-cuspidata_6  A Japanese Yew grown as a bonsai

Taxus_cuspidata_1  Foliage mixed with mature arils and female ‘cones’

Taxus_cuspidata_2  Different parts of a Japanese Yew, including pollen ‘cones’, arils, female ‘cones’, branches, and foliage. Art by Philipp Franz von Siebold and Joseph Gerhard Zuccarini from Flora Japonica, Sectio Prima (Tafelband).

Taxus_cuspidata_3  The various stages of aril development on a female tree

Taxus_cuspidata_4  A Japanese Yew grown as a bonsai.

Taxus_cuspidata_5 A Japanese Yew grown as a shrub/bush.

I do not own the rights of these images; all credit goes to its original creator(s).

Taxus_cupidata_image_sources

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