Thursday, June 4, 2015

Introduced species: Silene spp.

One rather distinctive-looking species that many people are likely to come across, even in cities, is Silene vugaris (bladder campion). This introduced species is native to Europe and now distributed across Canada and the US (US range map here, Canadian range map here).

Silene vulgaris - male flowers
I have posted the above photo before (quite some time ago now), but I'm posting it again because it really does show clearly what it is that is visually attractive about this plant (also, I have since developed some basic image enhancement skills and can increase contrast and sharpen images to improve their informative value, so this version is a bit better), which was introduced in North America for its ornamental value [1].

Silene vulgaris - whole plant
This plant is not known to prosper in wild native environments but is reasonably common in modified habitats [1]. It is listed as a noxious weed in both the US [2] and Canada [3].

Silene vulgaris - foliage
S. vulgaris has some interesting reproductive characteristics; it appears in many forms; the flowers can be male (such as the ones pictured in the first image, which only have stamens), others are female, eg the one below with only pistils, and some are hermaphrodites with both male and female parts and function (I don't have any photos of a hermaphrodite flower) [4].

Silene vulgaris - female flower
Another plant from this genus which is also introduced is Silene latifolia (white campion). It is also widely introduced in North America (US range map here, Canadian range map here). Like its close relative S. vulgaris, S. latifolia is listed as a noxious weed in both the US [5] and Canada [6].

Silene latifolia - whole plant
The foliage of S. latifolia resembles S. vulgaris, but is generally broader and larger.

Silene latifolia - flower - note the comparative lack of detail/subtlety in the veination of the bulbous section
Flowers in this species are unisexual (either male or female) [7]. All of the S. latifolia flowers pictured here are female.

Silene latifolia

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