Berberis thunbergii -- Japanese Barberry

See also Berberis vulgaris (Common Barberry)

Non-native* (Asia)

Other names:  Thunberg's Barberry, Red Barberry, Desert Holly

[1]

[4]

[3]

[10]
Photo of red/purple form by Evelyn Fitzgerald on Flickr under a Creative Commons license.

[1] For more detail see also eFloras.org



Notes:
B. vulgaris can be differentiated from B. thunbergii in a number of ways.
  •  The leaves of B. vulgaris have toothed edges, while the edges of the leaves of B. thunbergii are entire. 
  • B. thunbergii has single, unbranched spines along the stem. B. vulgaris may have double or triple branched spines.
  • Flowers (and fruits) of B. thunbergii hang down from stems singularly; flowers usually white. B. vulgaris has yellow flowers in longish clusters.
Refer to a comparative chart and key to these species (PDF) from the USDA Forest Service.

There are numerous cultivars of B. thunbergii, including dwarf, yellow, and purplish-red forms. Crossing among them and with feral populations may result in a reversion to green leaf colors. There is wide variation in the number of seeds produced by various cultivars, but once established and mature, nearly all cultivars (including those produced no fruit when first planted) show an increase in seed productivity over initial numbers, so cultivars advertised as "sterile" are not safe to plant. See Brand et al. 2012 for details.


References:


* Listed as invasive in natural areas by the Invasive Plant Atlas of the United States.

(Numbers in photo captions are photo credits, listed in the "Photo Credits" tab at the top of the page)