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Results tagged “april-26”

Apr 26, 2013: Linanthus dichotomus

The Traverse Creek Botanical Special Interest Area was established to protect a community of plants associated with the serpentine soils of the locale. Serpentine soils have high concentrations of metals like magnesium, nickel and chromium which few plant species can tolerate; these metals have an effect on soil chemistry and mineral availability. Species that do tolerate serpentine are often ecological specialists, adapted or evolved for serpentine environments.

Traverse Creek is ideal for photographers interested in both botany and time-lapse imagery. Lewisia rediviva, which is tolerant of serpentine soils and present here in quantity, will only open during the mid-day sun. Time-lapse imagery of the flowers opening and closing is possible from mid-morning to late afternoon. Conversely, the flowers of most plants of today's species are closed during the same time period. They only begin to open in the late afternoon, and then the flowers persist through the night and early morning. This is somewhat evident in my photographs, as the first image (with only one flower fully open in the mid-bottom centre) is from when I arrived on-site, and the third image is from when I left.

This species is Linanthus dichotomus, commonly known as evening-snow (Calphotos link, with more images). An annual species, it can sometimes be seen in dense stands when conditions are right, such as timely and sufficient rainfall (I believe this can occur at the Traverse Creek site, but not this year).

I should point out that the Jepson eFlora recognizes two subspecies of Linanthus dichotomus: subspecies dichotomus, which has the evening-open (or vespertine) behaviour, and Linanthus dichotomus subsp. meridanius, which has a daytime-open behaviour. Likely, this decision was in part based on the strength of the evidence from this paper: Chess, SK et al. 2008. Geographic divergence in floral morphology and scent in Linanthus dichotomus (Polemoniaceae). Am. J. Bot. 95(12):1652-9. doi: 10.3732/ajb.0800118. The scientists discovered significant differences between the scents of the two subspecies (by measuring the type and quantity of the floral volatile compounds). Compounds that typically attract nighttime moths were found in high concentrations in Linanthus dichotomus subsp. dichotomus, while Linanthus dichotomus subsp. meridanius had a suite of compounds more typically associated with attracting generalist daytime pollinators.

The El Dorado chapter of the California Native Plant Society shares more information about the Traverse Creek Botanical Special Interest Area.

Apr 26, 2012: Cladonia evansii

Cladonia evansii

One of the many highlights of our recent trip was a visit to the Ohoopee Dunes Natural Area near Swainsboro, Georgia, where Dr. Mincy Moffett gave us a tour of this uncommon ecosystem. The Ohoopee Dunes are the most extensive riverine sandhill formation in Georgia, and host a number of rare and threated animal and plant species.

One vignette of the tour was this location where Cladonia evansii, also known as powder-puff lichen or deer moss, was found in abundance. With its dense clusters of greyish-white round tufts, it looked like someone had assembled a collection of miniature tumbleweeds in the oak leaf litter (I think it's bluejack oak, Quercus incana). While we all admired the amount of this lichen in this location, Alan Cressler has a photograph of an even denser stand from a different tract of the Ohoopee Dunes: Cladonia evansii.

In the USA, Cladonia evansii is found along the coastal plain of the eastern seaboard, ranging from Texas to at least North Carolina (and perhaps even further north -- I can't tell on the map I've used). It is also found in the Caribbean. Its habitat preference is partially shaded or open ground, typically in sandy areas. Additional images are available from ForestryImages.org: Cladonia evansii and Sharnoffphotos.com: Cladonia evansii.

Apr 26, 2011: Pinus contorta var. contorta

Pinus contorta var. contorta

A trip to the Shorepine Bog Trail in Pacific Rim National Park Reserve did not yield the hoped-for sighting of the introduced Darlingtonia californica (seen as recently as last year, and introduced over ten years ago). I'll excuse it on being too early in the season, given the hesitating spring. I am a bit curious as to why Parks Canada staff allow the plants to persist, given that they are non-native in many definitions of that term, but perhaps they are doing some long-term monitoring.

It was, however, an opportunity to enjoy the natural "bonsai" of the shore pines in the area. The boggy area is much smaller in extent than Burns Bog, so it is far more difficult to isolate individual plants from the background--I opted for a texture photograph of the landscape instead.

Pinus contorta has 3 or 4 varieties depending on the taxonomic reference. Variety contorta, the shore pine, is described in the Silvics of North America: "The thick-barked trees are relatively small, short-lived, and inherently branchy. Now mostly confined to marginal sites (muskegs, dunes, serpentine soils, rocky sites), this race pioneered forest succession in the Pacific Coast region at the end of the lce Age. Needles are short, rather narrow, and have more stomata per unit area than the leaves of inland races. Flowering is abundant, and female strobili tend to mature earlier than the male. The cones are reflexed and persistent. Cones usually open not long after they mature, but serotiny is increasingly common toward the interior. Seeds are small to medium-sized, and germination is slower than that of the interior races. Early height growth nearly always is faster than that of inland populations at the same latitude. Local variations include a chemically distinctive northern muskeg ecotype extending south to western Washington."

Pinus contorta var. contorta is one of the Great Plant Picks for local gardeners.


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