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Results tagged “habit”

Jan 3, 2013: Pholistoma auritum

I learned today that California's Pinnacles National Monument is one signature away from becoming the USA's 59th National Park, so I decided to highlight something from my all-too-brief trip there a few years ago.

Pholistoma auritum is a small (to 15cm), fleshy annual species of California, Nevada and Arizona. In California, the species is found in "ocean bluffs, talus slopes, woodlands, streambanks, canyons, desert scrub" from elevations of 0-1900m (0-6200ft.). For the most part, it occupies the southern two-thirds of the state, with only one-few disjunct populations in the north. Common names for the species include fiestaflower or blue fiestaflower.

Oct 16, 2012: Larix lyallii

Today's write-up and photographs of Larix lyallii are courtesy of Bryant, BPotD work-study student. He writes:

These subalpine (or alpine) larches were photographed on the northeast face of Mount Frosty in British Columbia's E.C. Manning Provincial Park. Larix lyallii is one of my personal favorites for its unusual characteristics and its ability to survive higher altitudes and harsher conditions than most other conifers. Larix is one of the few genera of deciduous conifers (other deciduous conifers). In early/mid-September through early/mid-October in British Columbia, this species changes colour from green to a stunning golden-yellow. Larix lyallii grows in upper montane zones that would otherwise be considered alpine tundra (usually above the treeline of evergreen conifers), as well as on exposed rock outcrops. Its native range follows high alpine environments in southern (primarily southeast) British Columbia, southwestern Alberta and northern Washington, Idaho and Montana (distribution map).

Although trees of Larix lyallii are stunted by the long and harsh winters they endure, their trunks typically remain straight and upright (compared to displaying characteristics of Krummholz formation often seen among subalpine evergreen conifers). This is largely due to the deciduous characteristic, which helps to reduce the effects of winter desiccation and snow loading. The extreme hardiness of this species has helped it to become one of the longer lived species of conifer, with the known record holder being an individual 1,917 years old in Kananaskis, Alberta as of 2012!

Morphologically, Larix lyallii can grow up to 31m tall with a diameter at breast height of 215cm. As one might expect, larger specimens are generally found at lower elevations. The needles are quadrangular and grow in bunches of 30-40 atop abaxially keeled short shoots. They tend to grow in moist immature/rocky soil that is well drained. Plants grow at elevations between 1,900 and 2,380 metres, with slightly lower elevations in the North Cascades (1,830 to 2290m). Larix lyallii may also grow in association with Pinus albicaulis (whitebark pine), Abies lasiocarpa (subalpine fir), and Picea engelmannii (Englemann spruce) at the upper limits of their elevational distributions.

Oct 4, 2012: Jasper National Park

Jasper National Park

I was asked in the comments recently if I had time to photograph autumn colours. Last week, I was in the Alberta and British Columbia Rockies hoping to do just that, but because of the hot and dry autumn, colours were overall poor. In fact, many trees had crisped brown leaves instead of any sort of colouration. This photograph is from my 2011 trip. It's a good example of how photographs can omit--the split stream flows through a triangular piece of land bordered by roads (which you can see via the Google Map).

The yellow-leaved trees are young black cottonwood or Populus trichocarpa while I believe the conifers in the foreground are Engelmann spruce, Picea engelmannii. The other possibilities for the conifers are Picea glauca (white spruce) or the hybrid between the two species.

Aug 31, 2012: Isophysis tasmanica

Isophysis tasmanica

Nuytsia@Tas@Flickr is responsible for today's photograph from the Sentinel Range in Tasmania. Thanks for the photograph and introducing the genus to me (Isophysis tasmanica via the Botany Photo of the Day Flickr Pool).

Isophysis is one of 15 or so recognized genera of vascular plants endemic to Tasmania. The genus is monotypic, meaning Isophysis tasmanica is the only species. As noted by Nuytsia@Tas, Isophysis is the basal group in the iris family. In other words, it has been determined to be the earliest group to diverge from the rest of the Iridaceae. Sometimes, the terminology "primitive" is used instead (e.g., the most primitive group in the iris family), but that term carries some scientific imprecision and is generally avoided these days.

With its sometimes-nodding flower heads, reflexed tepals and superior ovary (unique among the Iridaceae for this characteristic), the species can superficially resemble some species of Erythronium (Liliaceae). The fan-shaped leaf clusters growing from the ground, however, clearly suggest iris family to me.

Plants of Tasmanian purplestar grow to 30cm (12 in.), and sport either the dark purple flowers seen in today's photo or occasionally pale yellow flowers. It is a species of alpine and subalpine environments in Tasmania, preferring habitats dominated by heath or sedges. It might be something we could grow in the Australasian section of the E. H. Lohbrunner Alpine Garden here at UBC, so I've suggested it to the Curator for the area, Brent Hine.

Jun 4, 2012: Hemieva ranunculifolia

A question I am frequently asked at presentations, particularly after presenting the "new name" of a species, is: "Why do plant names change?". The answer invariably is, "Well, it depends...", followed by an elaboration with some examples. I can apparently add today's species to my repertoire of examples, as it is a relatively straightforward one to explain.

If you are familiar with this species, you will likely know it as Suksdorfia ranunculifolia, or buttercup-leaved suksdorfia. That's been the name attached to it for about a century, though this has been recognized as a distinct species for almost two centuries. It was first published as Saxifraga ranunculifolia by William Hooker in 1832. Only four years later, the prominent (but controversial) botanist Constantine Rafinesque published his assertions that not only was it not a saxifrage, but it was also from a previously-undescribed genus. In 1836, he proposed the name Hemieva for the genus, and renamed it Hemieva ranunculifolia (and, more technically, Hemieva ranunculifolia (Hook.) Raf.). This name languished for a long time, disregarded for the most part--this was toward the end of Rafinesque's life, when he was generally ignored.

In 1879, Asa Gray described a new taxon in the saxifrage family, Suksdorfia violacea, for which he had to erect the genus Suksdorfia. Twelve years later, Adolf Engler proposed transferring Saxifraga ranunculifolia Hook. (aka the ignored Hemieva ranunculifolia (Hook.) Raf.)) into Suksdorfia, and this became the generally-agreed upon standard for beyond the next century: Suksdorfia ranunculifolia (Hook.) Engl.. With the transfer of Saxifraga ranunculifolia into Suksdorfia, strictly speaking, both should have been renamed Hemieva, but Rafinesque's name was rejected.

With the advent of molecular techniques in the late 20th-century, some of the new data gathered suggested that Suksdorfia ranunculifolia possibly had an ancient hybridization with a species of Boykinia, such that determining relationships based on chloroplast DNA put this one of the two Suksdorfia species as a closer relative to the group of Boykinia species than to its sister taxon, Suksdorfia violacea. However, an assessment of the ITS region showed that the two Suksdorfia species grouped together and were closely related to Bolandra, in accordance with the existing morphological evidence (see: Soltis et. al. 1996. Discordance between ITS and chloroplast topologies in the Boykinia group (Saxifragaceae). Systematic Botany. 21(2):169-185.). The authors concluded that some taxonomic revision may be required.

As part of the development of the 2nd edition of The Jepson Manual, the editorial committee reviewed the 1996 paper as well as subsequent evidence, and made the determination that Suksdorfia ranunculifolia should be recognized as being in a genus distinct from others in the Saxifragaceae. Due to the principles of priority (Rafinesque was the first to place this taxon into a distinct genus), Hemieva ranunculifolia, first proposed in 1836, became the "new" name for Suksdorfia ranunculifolia.

Hemieva ranunculifolia is native to western North America, reaching its northern extent in British Columbia and Alberta and its southern extent in California, where it is ranked as "fairly endangered" in the state. The plant in today's photograph was growing on a wet rock wall that had been blasted for a railroad right-of-way. Only a few plants in the shadiest spots remained in bloom as of two weekends ago.

May 29, 2012: Osmunda regalis var. spectabilis

Osmunda regalis var. spectabilis or royal fern, is one of my favourite ferns. Native to much of eastern North America, I first encountered it near Ottawa a couple summers ago and subsequently in North Carolina, Georgia, and Tennessee. It is not yet in the collections at UBC Botanical Garden, though we hope to procure some wild-collected spores for growing in the Carolinian Forest Garden.

In the past, this was sometimes thought to be equivalent to the Eurasian and African Osmunda regalis. It was also sometimes considered to be its own species, Osmunda spectabilis. Currently (according to USDA GRIN taxonomists), it is recognized as one of three varieties of Osmunda regalis, with the third being the South American Osmunda regalis var. brasiliensis.

Preferring moist habitats such as wet forests or streambanks, royal fern can reach up to 2m (6 ft.) in height under ideal conditions (such as in gardening situations).

Mar 26, 2012: Ranunculus triternatus

If it isn't too much to have two similar-looking buttercup family representatives in a row, here are some images from just over a week ago.

Ranunculus triternatus (syn. Ranunculus reconditus) is an almost-endemic to the Columbia Gorge area of Washington and Oregon. A single location near Elko, Nevada and another in southeastern Idaho have also been reported. However, there is little information about the latter two reports online that I can find--most seem to be derived from the Flora of North America account for Ranunculus triternatus. Two common names are in use for the species, obscure buttercup and Dalles Mountain buttercup (the latter referring to the area where it is found near in Washington and Oregon).

Most research and conservation monitoring work has been done with the Washington and Oregon populations. According to the Center for Plant Conservation, ten occurrences of Ranunculus triternatus are known in these states: "In WA, 8 occurrences known since 1987. Populations range from "100+" to "several hundred." One other occurrence was reported in 1938, but the location data is not complete. Either it cannot be re-located, or it has been extirpated (WNHP 2000). 2 occurrences are currently known in Oregon with population numbers ranging from 50 to 800 (ONHP 2000).". I suppose that puts the number of individual plants worldwide at around 3500 +/- a thousand or so. I observed about seventy in flower during my brief visit to the area on a cloudy late afternoon.

As noted by Paul Slichter on his page for Ranunculus triternatus (includes additional photos!), the species "is found primarily in fairly undisturbed grasslands or areas of mixed grasslands and sagebrush. Plants are generally found in deeper soils among bunch grasses rather than in the thinner rocky poorer soils which are frequently found on the hillsides".

Additional photographs are available via the Oregon Flora Image Project (Ranunculus triternatus) and a scan of a specimen collected by Thomas Howell is available via Oregon State University Herbarium: Ranunculus triternatus.

I also had a request from a BPotD reader to include a bit of a photographic information from time to time. For these photographs, and for most photographs of buttercup flowers, I often find it necessary to underexpose the image. A camera-metered exposure will often blow out the yellows or introduce white spots on the petals due to the petals' high reflectivity (you can see the white spotting beginning to occur on the last photo). A polarizer can also be useful, but it is perhaps more important to make the photographic attempt on a cloudy day. I had also photographed some Ranunculus occidentalis this day, but I've thrown away most of those images because they were taken in the sun and no detail was left in the flower petals (I kept a couple for reference to remind me that it was out in bloom in the region on that date).

Mar 20, 2012: Ribes sanguineum 'White Icicle'

The hotel I'm staying at apparently prevents me from uploading images for BPotD because of some sort of file size restriction, so I'll have to find another venue for the rest of the week. In the meantime, I did have this entry I started to write last year until a question came up that has so far proven unanswerable, so I'll share it instead.

The cultivar name 'White Icicle' for this flowering currant was published in 1986 in HortScience 21(3):362, by Dr. Gerald Straley of UBC Botanical Garden (deceased 1997). Commercially introduced in 1988 as part of UBC Botanical Garden's plant introduction program of the time, it was a variant that had originally been selected in 1973 from Vancouver Island. Compared to other white-flowered cultivars, it is generally considered more desirable as it has pure-white flowers and it is a more vigorous plant overall. While visiting some public gardens in Washington and Oregon this past week, I've spotted it planted prominently near the entrances. It is, at least regionally, indeed deserving of being one of the Great Plant Picks.

The question I've yet to answer is why the Royal Horticultural Society's Plantfinder (which we use as our initial reference for cultivar names in UBC Botanical Garden) lists the cultivar as Ribes sanguineum 'Ubric', and instead notes that White Icicle is a trademark (or a commercial designation with financial rights and responsibilities). I've searched the US, UK and Canadian trademark databases, and came up with zero results for the combination "white AND icicle". I also don't believe the Botanical Garden ever registered trademarks for any of its introductions, though more digging in the archives may prove me wrong.

Feb 28, 2012: Sedum moranii

Rogue River stonecrop is endemic to southwest Oregon, where it is found only along a less than 96km (60mi.) strip of the Rogue River and its tributaries. It is considered a Sensitive Species in Oregon and Critically Imperiled by the USDA. Threats to remaining plants listed by the USDA include: horticultural collecting for rock gardens, trail maintenance, recreational use of its habitat, and flooding. I've seen the result of horticultural overcollecting on other species (e.g., Cistanthe tweedyi), and I would say that there isn't much apparent evidence of plant-collecting at this site. In the instance of the Cistanthe, it was quite apparent that the density of individuals in a given area was higher (sometimes much) where plants were inaccessible. Here, for the few plants that I observed (one didn't have to go far), most were easily accessible both in terms of the distance from the vehicle and within 2.5m (8 ft.) up the face of the cliffs. A few plants even had potential for "drive-thru" photography--you could sit in your vehicle and photograph them out the side window.

Sedum moranii is named in honour of the now recently-deceased Dr. Reid Moran (scroll down linked page for short article), a US-born botanist (1916-2010). He was the Curator of Botany at the San Diego Natural History Museum from 1957 to 1982 and the author of the Flora of North America treatment for the Crassulaceae.

You can read the Flora of North America account for Sedum moranii for more or see additional images via Dr. Gerald Carr: Sedum moranii.

For local readers in the Vancouver, BC and Seattle, WA areas: in Vancouver, the Beaty Biodiversity Museum is hosting a photography exhibition called Interaction beginning March 6th, which will include sixteen photographs of mine. Read more on the Beaty's events page. For those of you in or around Seattle, the Miller Library is hosting a botanical art exhibit from March 2nd to March 29th in conjunction with the conference "Conserving Plant Biodiversity in a Changing World: A View from NW North America". I have two photographs in that exhibit, as well.

Feb 16, 2012: Quercus agrifolia

Quercus agrifolia

Thanks to Damon Tighe@Flickr for submitting his photo of Quercus agrifolia from Oakland, California (via the Botany Photo of the Day Flickr Pool). Damon's photostream on Flickr has quite a few recent botanical images from California.

A photograph of the acorns and foliage for coast live oak or California live oak is available from a previous Botany Photo of the Day entry, Quercus agrifolia. In trying to track down the meaning of "live oak" when it is used in a common name, my conclusion so far is that all live oaks are evergreen and North American, but not all evergreen North American oaks are known as live oaks. Also, the live oaks belong to different taxonomic groupings within Quercus. Five species, in Quercus Section Quercus, or the white oaks, are native to southeast and south-central North America. Four species given the common name live oak are native to southwestern North America. Three of these species are in Quercus Section Lobatae, the red oaks, and one is in Quercus Section Protobalanus, or the intermediate or golden-cup oaks.

Calphotos has many images of this iconic Californian tree species: Quercus agrifolia. Quercus agrifolia can also be found in Baja California.

Feb 10, 2012: Melliodendron xylocarpum

Melliodendron xylocarpum

Melliodendron xylocarpum was featured in the first Botany Photo of the Day, nearly seven years ago. At the time, Douglas Justice, UBC Botanical Garden Curator of Collections, commented:

"Melliodendron xylocarpum--the name means something like woody fruited honey tree--is, according to the 1998 book "Rare and Precious Plants of China," native to China's southern provinces at between 500 and 1500 metres. Not an elevation to give much confidence in its cold hardiness, but because it has wintered here completely unscathed since planting (1996), I suspect that it had a more extensive historical range. Melliodendron is in Styracaceae (snowbell family) and monotypic (a single species in the genus) and is probably closely related to Rehderodendron and Sinojackia, both of which have similar ribbed, woody fruits...This [2005] is the third or fourth year that Melliodendron has flowered at UBC. Thankfully, we have 7 individuals--all planted in 1996, all, we assume from the same seed lot (the plants came to us from a commercial supplier)--and the one pictured, which is our finest specimen, will be spared the now constant crush of traffic when the others start flowering more prolifically."

Today's photograph is from May of 2011. This is a different plant from the previous entry, and it helps to show some of the flower colour variability between individuals (here, noticeably pinker).

Feb 4, 2012: Castilleja coccinea

It is likely this is the first member of the Orobanchaceae that I ever knowingly encountered--a small patch of scarlet Indian paintbrush grew on the edge of some gravel pits about 10km from my childhood home. This species is perennial, so that patch is possibly still there if someone hasn't torn up the rocky soil with an ATV or the like. I do remember being taken out by my parents specifically to see that patch on one or two occasions.

Castilleja has somewhere in the neighbourhood of 160-200 species, and almost all of these are in western North America. Castilleja coccinea is one of the exceptions, as it is broadly distributed across eastern North America. These plants, with their scarlet-red bracts, were photographed in early May.

Oct 20, 2011: Salix bebbiana (tentative)

A tentative species identification today, as making a positive identification of a willow is usually a non-trivial matter involving a wide-ranging suite of characteristics. In this case, I have some close-up photographs that more clearly show the leaf shape (obovate), the not-glaucous nature of the branches, and what appear to be yellow buds against the reddish-branches. Combined with the habitat, the known species from the area, and the habit (a small shrub not forming a colony), and I reached the conclusion of Salix bebbiana--but I am entirely willing to be corrected! For more on willow identification, see A Guide to the Identification of Salix (willow) in Alberta (listed in the references).

Assuming the yellow-leaved plant in the photographs is Salix bebbiana, then this is a representative of a species native to much of North America north of Mexico, with the exception of the southeast USA. Bebb's willow or beak willow is also found in far eastern Russia and Siberia. Like the Betula glandulosa from a few days ago, this is an important browse species (though not this particular individual, given its precarious location).

There are somewhere in the vicinity of four hundred willow species, in addition to a number of naturally-occurring hybrids. The majority of these are native to the temperate and arctic northern hemisphere. Unfortunately, when a few species were introduced into Australia for erosion control, they eventually became invasive.

Oct 17, 2011: Betula glandulosa

It seems like the prehistoric plant series was well-received while I was on vacation; on behalf of Alexis, thank you for the comments and emails.

My trip to Jasper National Park a couple weeks ago didn't quite meet my hopes for autumn colour. It seems like heavy winds had already hit some of the trees and shrubs, so plants ranged from fully-defoliated to still-green, with not a lot in the middle (much of what had turned had abscised with the winds). Still some pleasant pockets of colour, but it would have been a more showy display of yellows and oranges had I arrived a few days earlier.

On the other hand, there was a different set of colours to be found with the dwarf (or bog) birches. I now wish I had spent more time making photographs like the vertical one, as I like the effect of the out-of-focus leaves in the background. Fortunately for me, Betula glandulosa is widely distributed in western and northern North America (including much of British Columbia), so I needn't travel as far for such images in the future.

Also present in this less-frequented area of the park were numerous ungulate hoofprints. I presume these were moose, as Betula glandulosa is the preferred browse plant of a moose's summer forage diet in Jasper National Park. In the winter, the buds are eaten by ptarmigan and grouse. Important to keep in mind for next time, it seems that in the central Canadian Arctic, "Grizzly bears...constructed their dens under bog birch cover more than any other plant species. Bog birch was present at 84% of 52 den sites, and it was the highest in percent cover around den entrances. Bog birch roots formed ceilings of several dens studied". I imagine these would more typically be found in rocky slope areas as opposed to the more boggy region where today's photographs were taken. On the topic of animals and plants, I think perhaps that will be the next BPotD series, so if you have photographs of a mammal using a plant in some way (food, shelter, etc.) with both the mammal and plant identified, send me a note.

Additional photographs of Betula glandulosa are available via the Flora of the Canadian Arctic Archipelago (follow links at bottom of page).

Sep 29, 2011: Rainiera stricta

Known only from the Cascades of Washington and Oregon states, Rainiera stricta is the sole member of its genus. Within the highly-diverse aster family, Rainiera belongs to the tribe Senecioneae, so it is most closely-related to composite genera such as Senecio, Packera (ragworts and groundsels), Petasites (butterburs) and Luina (silverbacks). It is perhaps most closely related to the latter, as it was at one time described as being in Luina. That taxonomic hypothesis seems to have been rejected, with some going so far as to commonly call it "false silverback". Other common names include tongueleaf rainiera or simply rainiera.

These photographs are from August of 2009, and this plant was indeed growing in the habitat and elevation as described by Flora of North America for Rainiera stricta: "Moist soils, open slopes, meadows; ... 900-2000m". The soils and vegetation were so moist on this particular day (a heavy, cold rain) that I had to change pants and shoes upon returning to the vehicle.

Additional photographs of the species are available from the Burke Museum: Rainiera stricta.

Sep 28, 2011: Aloe dichotoma

Aloe dichotoma

Thank you to occasional BPotD photo contributor Amir Auerbach of Israel for sharing today's photograph via email. I'm making the assumption based on the file name of what he submitted that today's photograph was taken in the Richtersveld area, a high desert landscape in the Northern Cape province of South Africa.

Aloe dichotoma, the quiver tree or kokerboom, is endemic to this area of South Africa (and neighbouring Namibia with its Namib Desert). Its common name of quiver tree is due to the species being used by the indigenous peoples for the production of quivers. These arrow-holding tools were constructed by hollowing out lengths of mature branches, then covering one end with a piece of leather. Dead plants of this species are also hollowed out and used as natural fridges for meat, vegetables and water.

The South Africa National Biodiversity Institute has an always-excellent article on Aloe dichotoma for additional reading.

May 26, 2011: Paeonia brownii

Another entry today compiled and mostly written by Alexis:

Today's photo was submitted via email by Liesl Zappler, who writes: "After reading The Collector: David Douglas and the Natural History of the Northwest by Jack Nisbet, and finding out about the native Brown's peony, I was determined to find it this spring. It's been known to be in the Blue Mountains of Washington, as well as in northeast Oregon. Thanks to the rangers at the Pomeroy, WA and Pendleton, OR National Forest stations, I was able to find the peonies east of Athena, OR on Wild Horse Rd." Thanks, Liesl!

Paeonia brownii, a native to the western United States, is a fleshy leafy plant that usually has several clustered stems. Its leaves are deeply lobed and bluish-green in colour, while its solitary flowers (a single flower on each peduncle) are greenish and reddish-brown. Paeonia brownii habitats range from ponderosa pine forests to sagebrush deserts.

The licorice-tasting roots of Paeonia brownii were used by First Nations to make a tea for healing lung illnesses. In fact, the genus name Paeonia originates from the name Paeon (or Paean), who was the physician of the Greek gods.

Though some consider Paeonia brownii to be the only peony species native to North America (and divided into two subspecies), two species are recognized by the Flora of North America (representing the general consensus). Paeonia californica (image) is found in southern California to northern Mexico.

May 11, 2011: Cordylanthus palmatus

Today's photographs were shared via the UBC Botanical Garden forums by member mollymCA: Alkali Sink Vernal Pools, Livermore, CA. Thank you very much! Molly has also written a great account about this area, so I'll share her writings here. Molly writes:

The Springtown Vernal Pools should be especially spectacular this year of late rains. This area, enclosed by development, has so far been saved by the presence of the endangered (FE/SE: Federal and State) Cordylanthus palmatus, palmate-bracted bird's beak. It is in the Scrophulariaceae (Daniel -- now in Orobanchaceae) and thus a relative of Indian paintbrush, and like many in the family a hemiparasite on roots of other plants. It may be able to survive without a root association, but is said to develop more color in the bracts--the 3-pronged structures that clutch the stem--according to the extent of such a relationship (if true, this plant hadn't yet found a friend!).

The Cordylanthus is a salt-excreter and you can see the crystals on the rather succulent leaves and bracts. The flowers (like those of Indian paintbrush) are insignificant even when fully out -- on May 9, 2008 they were not quite fully extended from the bracts.

The white areas in the landscape photograph are dried vernal pools and stream areas, crusted with the salt that accumulates over years of leaching from the soil into the landlocked depressions (or nearly so: there is a rather feeble flow out from some of the streams). The bird's beak would be found on the edges of the salt areas.

The green plant growing with the Cordylanthus palmatus is Salicornia, also called pickleweed, and the dry stuff lying on the ground is dormant Distichlis spicata, both typical of salty or salty-alkaline swampy areas.

Botany resource link (added by Daniel): Botany Photo of the Day was featured in the latest publication of the Berry-Go-Round blog carnival over at Foothills Fancies: check out Issue No. 39 of Berry-Go-Round to see a great selection of recent plant- and botany-based writing around the web.

May 10, 2011: Cornus florida

Cornus florida

A bit of a silly common name for this small tree, flowering dogwood (all dogwoods of reproductive age have flowers...), but that shouldn't detract from its springtime elegance. Cornus florida is another native of the eastern USA, but also nudges into Canada at the extreme edge of southern Ontario. A subspecies, Cornus florida subsp. urbiniana, is only found in eastern Mexico.

Cornus florida is threatened throughout much of its range thanks to the introduction of a fungus in the mid-1970s, Discula destructiva. Fungal infection of these dogwoods causes the disease dogwood anthracnose. Infection may or may not be terminal for individual trees, but it also weakens the trees and makes them susceptible to insects or other diseases. Over a long period of time, as random events occur and accumulate, significant mortality may result and this seems to be indicated in Jenkins, M. and White, P. 2002. Cornus florida L. Mortality and Understory Composition Changes in Western Great Smoky Mountains National Park. Journal of the Torrey Botanical Society. 129(3): 194-206. Jenkins and White found that higher relative mortality occurred over the two or so decades from 1977-1979 to 1995-2000 with smaller trees, and in cove forests and alluvial forests.

Read more about Cornus florida via the Silvics of North America or see additional photographs via the USDA PLANTS database: Cornus florida.

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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