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Results tagged “september-17”

Sep 17, 2014: Juniperus maritima

Bent, but not broken, this seaside juniper is one of a small population of at most a couple dozen individuals growing in Washington's Deception Pass State Park. These particular plants persisting against wind and saltspray form an atypical ecotype, as no other population is known to grow in this form and in a sand dune habitat. Typically, Juniperus maritima is an upright tree of the rocky margins of water bodies. The largest two known populations of several hundred plants each are in lands bordering Washington's Puget Sound (another common name is Puget Sound juniper), but its range extends northward into lands adjacent to British Columbia's Strait of Georgia. If geography is to be incorporated into a common name, a more inclusive moniker could be argued (e.g., Salish Sea juniper).

Juniperus maritima was scientifically described and published in 2007 (with a type specimen collected from Brentwood Bay, British Columbia). It may be hard to believe that a tree species near large urban areas of North America could escape the notice of botanists until 2007, but part of the reason for this is its extremely close resemblance to the Rocky Mountain juniper, Juniperus scopulorum. To be fair, Arthur Lee Jacobson (in his excellent write-up about Juniperus maritima) points out that the eminent botanist Leo Hitchcock wrote (in 1969): "Plants from the islands of Puget Sound appear to differ somewhat from those [Juniperus scopulorum] east of the Cascades in having the juvenile foliage longer-persistent and in producing cones [berries] that are less fleshy and rather consistently 1-seeded and it is believed not improbable that they will prove to constitute a distinctive race of the species." It did take nearly 4 decades for that distinctiveness to be recognized scientifically, with convincing data coming from chemistry (terpenoid analysis) and genetics (ITS sequences).

More on the subtle physical differences between Juniperus maritima and Juniperus scopulorum can be gleaned from Botanical Electronic News #387 (January 17, 2008): Juniperus maritima, the seaside juniper, a new species from Puget Sound and Georgia Strait, North America. The original paper is available as well: Adams, R.P. 2007. Juniperus maritima, the seaside juniper, a new species from Puget Sound, North America (PDF). Phytologia 89(3):263-283). Additional photographs of this species can be seen via E-Flora BC (Juniperus maritima) or the Burke Museum Herbarium's image collection: Juniperus maritima.

Sep 17, 2013: Dierama erectum

Dierama erectum

This rainy-day photograph is from last October, taken here at UBC Botanical Garden. Dierama erectum doesn't seem to have a vernacular name, though I suppose upright fairybells or upright wandflower would work. This photograph isn't a good example of the upright spikes of flowers that help distinguish it from its pendulous-flowered counterparts because of the mass of the water on the blossoms.

The name and description for this species were only scientifically published in 1988, even though a specimen was collected at least as early as 1977. In the past few decades, the species has become popular in cultivation. Its fate as a wild species is much less certain. Recent conservation assessments of this South African endemic species have determined it is endangered, with the justification for that status as "Known from a few subpopulations at two locations, in a very small area between Vryheid, Ngome and Paulpietersburg, northern KwaZulu-Natal (EOO 1800 kmĀ²). Most subpopulations remain in grassland fragments owned by a commercial forestry company and are all declining due to overgrazing. There may be a few other undiscovered locations on privately owned land, but probably not more than five" (EOO means extent of occurrence).

Research being done at the University of KwaZulu-Natal by Motselisi Jane Koetle has helped to establish a micropropagation protocol for the species: In vitro propagation of Dierama erectum. Being able to generate 15137 plants from one explant in a year would significantly bolster the number of individuals. However, since micropropagation only produces clones, it is but one element of a successful species restoration strategy, as it is ideal to preserve as much genetic diversity of the species as possible (see disease and monoculture).

Sep 17, 2012: Matelea reticulata

Matelea reticulata

Bryant is the author of today's entry:

A big thank you to Monceau@Flickr for today's photograph of Matelea reticulata. Native to Texas and northern Mexico, netted milkweed or green milkweed vine is a deciduous perennial vine typically found in shrubby thickets on rocky hillsides. Matelea reticulata is placed in the subfamily Asclepiadoideae of the family Apocynaceae (dogbanes). Like many other milkweeds, plants of Matelea reticulata can host butterfly and moth larvae, including the monarch and queen butterflies.

Members of the Asclepiadoideae (a subfamily of the Apocynaceae) undergo pollination in an unusual way. The small pillar in the centre of the flower is known as the gynostegium. Unlike a "textbook" flower with individual stamens and a separate style with stigma, the gynostegium is a fusion of the stigma, style and stamens. Also, the pollen of flowers in the Asclepiadoideae are often stored in sacs, known as pollinia. These are generated near the base of the gynostegium, where the anthers are located. Insects are attracted to visit nectaries on the flower, and in doing so may have pollinia latch onto their legs. Upon visiting additional flowers, if the insect's leg slips into a stigmatic slit (where the receptive surface of the stigma is located in the gynostegium), it can deposit the pollinium, and pollination occurs. The adaptive advantages of this approach remain under discussion, however the saying, "putting all of your eggs in one basket" definitely comes to mind. To see an example of hand-pollination in a milkweed, see this video on pollinium insertion.

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