There are approximately 35 species of spruce in the world. Picea mariana, or black spruce, is one of seven that are native to North America (north of Mexico). In comparison, China has sixteen native species.

Black spruce is distributed throughout Canada, Alaska and some northeastern US states, where it is typically a plant of wet organic soils (e.g., swamps and bogs) (distribution map).

Links to investigate: the Silvics of North America factsheet on Picea mariana, the always-excellent conifers.org page on the species, and Picea mariana in the Flora of North America.

I also note that the Plants for a Future database page on Picea mariana cites a reference stating that "The sawdust, the resin from the trunk and even the needles can cause dermatitis in some people." I don't think I ever received dermatitis from trees while walking through bogs in Manitoba, but I do recall a slight burning feeling on my forearms from the many light scratches I received from the sharp dead lower branches.

Thanks to Douglas Justice for writing today's entry. The photographs are from my recent trip to California. Douglas writes:

Up until 2006 and the publication of a paper by D. P. Little, the genus Cupressus L. was thought to be a northern Hemishere genus distributed roughly evenly (in numbers of species) between the Old and New Worlds. However, the New World cypresses (including Cupressus nootkatensis and the northern Vietnamese Cupressus vietnamensis) are now believed to be more closely related to the genus Juniperus than to the Old Word cypresses. You can read more about this change and the possibility of further name changes here.

Whatever name is applied to this species, it is a beautiful and iconic tree, forming huge, densely layered crowns with often picturesque twisted stems and braided bark. In the wild, it is known only from the Monterey Penninsula on the central California coast (see Cupressus macrocarpa on Wikipedia), but it is now very widely grown in horticulture. In gardens, it is primarily valued for its dark, dense foliage and fast growth for screens and windbreaks, but there are numerous mutant forms with a variety of branching and foliage effects (weeping, fastigiate, golden, etc.) and these appear to be extremely popular as specimen and accent plants. Despite the name, the cones of Callitropsis macrocarpa are not the largest of the cypresses. They are somewhat smaller than those of Callitropsis guadelupensis, a species from the island of Guadelupe, off the coast of Baja Cailfornia (and also smaller than those of the Italian cypress, Cupressus sempervirens). See a cone size comparison via Michael P. Frankis's wonderful cone collection.

Callitropsis macrocarpa grows well where winters are mild and there is plenty of humidity, tolerating wind and salt well, but the species doesn't fare well at all in areas with both high summer heat and humidity. Monterey cypress is the parent of the formidable Callitropsis × leylandii (C. nootkatensis × C. macrocarpa) (syn: ×Cupressocyparis leylandii), Leyland cypress, to which it lends considerable influence (most would be hard-pressed to guess the other parent from the appearance of this hybrid). Locally, both the species and its hybrids are susceptible to cypress tip moth (Argyresthia cupressella) and to cypress canker (Seiridium cardinale), but only where summers are hot (see this Australian fact sheet on cypress canker).

Thanks again to Douglas Justice for both today's write-up and photographs.

As I wrote the other day, last year at this time my wife and I were in India. Driving through Corbett Park on the way to our “forest rest house,” we passed through forested rolling hills and crossed a number of washes and streams. It was while bouncing along over one of these boulder-strewn washes at about 1200m elevation that I noticed what were clearly pine trees in the distance. We did stop, after much pleading, but I had to take the photographs from inside the vehicle (it is a tiger reserve).

Pinus roxburghii is a fairly wide ranging species, common in the Himalayas at low elevations from Pakistan in the west through northern India and Bhutan in the east. Both from a distance and close-up, I guessed that it was a three-needled pine, reminiscent (at least to me) of Pinus ponderosa (western yellow pine). Chir pine is somewhat distantly related to any of the North American three-needled pines, however. According to most accounts, this species is more closely related to Pinus pinaster (maritime pine) and Pinus canariensis (Canary Islands pine). Keith Rushforth (in Conifers, Christopher Helm, London, 1987) notes that fossils show Pinus roxburghii and Pinus canariensis once formed a single population across southern Europe to the Himalayas.

Chir pine is named for the so-called father of Indian botany, the Scotsman William Roxburgh. As for the etymology of the name “chir,” I can only find that in Urdu, chir means milk. My guess is that the resin, which is utilized for a wide variety of uses (see the Wikipedia entry), is white. Perhaps one of our Indian Botany Photo of the Day correspondents and/or a chir pine expert can expand on this.

Thank you to Regina Alvarez, Director of Horticulture and Woodland Management at the Central Park Conservancy in New York, for sharing today's photographs. Much appreciated!

The first photograph of bald cypress is from an ice storm that occurred a couple weeks ago, while the landscape perspective photograph of the stand of trees includes the same individual in autumn colour, along with one of the park's visitor centers.

Taxodium distichum was previously featured on BPotD, so I'll add two more links to the mix: Taxodium distichum from the Lady Bird Johnson Wildflower Center's Native Plant Database and the Kemper Center for Home Gardening's entry on Taxodium distichum both provide additional photographs, as well as cultivation, descriptive and economic information about the species.

Today's photographs and entry are courtesy of Douglas Justice, the garden's Curator of Collections. – Daniel

This pine is a favourite of mine, being both exuberant in growth and delicate in overall effect. Himalayan pine produces long, relatively soft needles in fascicles of five on long, shoots that retain their smooth silvery sheen for many years. See the Wikipedia entry and the page at conifers.org for more information. The blue-green of its needles, the shape of its cones and the regular, whorled branching is somewhat typical of white-pines (compare with Pinus strobus, Pinus monticola and Pinus flexilis), but its crown is broad, at least in the cultivated material I’ve seen. According to Keith Rushforth (Conifers, Christopher Helm, London, 1987), nearly all of the soft pines (Section Strobus) “do not like exposure.” In the David C. Lam Asian Garden, the Pinus wallichiana pictured is sheltered on a southeast-facing hillside with a variety of other exotics under mature Abies grandis (grand fir).

VanDusen Botanical Garden (Vancouver’s other botanical garden) also has a collection of Pinus wallichiana in its Sino-Himalayan Garden, and like ours, the trees are of unknown provenance. Sometime in 1981, I was working at Massot Nurseries, a large wholesaler in Richmond, BC (just south of Vancouver). One of my duties as a shipper was alternate truck driver, and one day I had occasion to deliver a load of these Himalayan pines (now in #5 pots) to the still developing VanDusen Garden. The plants had originally been grown at Hybrid Nurseries, a forest seedling grower, whose owner at the time, Bruce Morton, was interested in disseminating exotic conifers around the Vancouver area. At VanDusen, I met a kindred spirit in Gerald Gibbens, the gardener for the Sino-Himalayan Garden at VanDusen. Gerry had recently returned from an internship at Windsor Great Park and was still high on the experience, which he explained in some detail as we unloaded the pines. Ten years later, Gerry made it possible for me to intern at Windsor—a seminal experience for me. Windsor was not only a way to ease myself out of the nursery industry, but it was my starting point on the road to a career in public horticulture. What a great tree!

Today's photographs and entry are courtesy of Douglas Justice, the garden's Curator of Collections. – Daniel

Taiwania, or coffin-tree, is currently recognized by most authorities as consisting of a single species, which ranges from SW China to Myanmar (Burma) and Taiwan. According to the entry on Wikipedia for Taiwania, it is the tallest species in Asia, at 80m.

UBC Botanical Garden has three wild collections of Taiwania cryptomerioides, all derived from sites in Taiwan: Tahsuehshan, 2200m (accession pictured), Tachien, 2200m, and Hsiuluan, ~ 2000 m (foliage detail accession pictured). Little seed is available outside of Taiwan, as the species is rare and now protected in China. Despite the relatively low elevation and southerly provenance of this species in Taiwan, our plants appear to be reasonably hardy in the David C. Lam Asian Garden (USDA Zone 8), having never suffered frost damage in more than 20 years. Our taiwanias are located in a variety of environments, in forest under the shade of mature Alnus rubra, Acer macrophyllum, Abies grandis, Thuja plicata and Tsuga heterophylla, and in the open. Some plants receive irrigation (our thin soils and dry summers necessitate supplemental irrigation for many ornamentals), but most have to fend for themselves. A few of the plants in the open display yellowing foliage, but all plants are growing strongly and many are strikingly beautiful, displaying the typical drooping branch tips, blue-green curtain-like foliage and narrow conical habit.

None of our plants has started coning (as outlined in our interpretive sign), although there was a report in 2006 of what could have been male cones in the upper branches of one of our oldest trees. To our knowledge, no cultivated Taiwania in a North American or European botanical garden has ever produced a seed cone. There is a point to wanting our taiwanias to produce seed cones, beyond having bragging rights. Upon reaching reproductive maturity, the leaves change from awl-shaped (similar to Cryptomeria japonica) to smaller, more appressed and scale-like (see illustration of a branch with cones via conifers.org). This is example of foliar dimorphism due to heterochrony. More significant (from a botanical point of view) is that Taiwania appears to have “features crucial to the understanding of the evolution of the cupressaceous cone, characteristic of the families Cupressaceae and Taxodiaceae, and provide further evidence for the need to merge these families”. See Farjon and Garcia's Cone and ovule development in Cunninghamia and Taiwania (Cupressaceae sensu lato) and its significance for conifer evolution and Schulz and Stützel's Evolution of taxodiaceous Cupressaceae (Coniferopsida).

Pinus monticola, or western white pine, is native to western North America. It can be found at many elevations, from sea-level to 3350m (11000 ft.), but local conditions dictate the elevation range of the species. This particular tree was growing at around 600m (2000 ft.) along Hurricane Ridge in Olympic National Park. The trees growing at high elevation can only be found at the southern end of its distribution range, in the Sierra Nevada.

Whenever a North American species conifer is featured on BPotD, I'm obliged to link to two excellent resources: Pinus monticola from The Gymnosperm Database and Pinus monticola from the Silvics of North America.

I find it grimly amusing to note that toothpicks are mentioned as one of the economic uses of western white pine in the Silvics of North America factsheet. It brings to mind a quote I've failed to recall precisely, but was along the lines of: “Surely the supreme value [of trees] is not toothpicks”.

White pine blister rust (photo gallery), a foreign fungal pathogen introduced into North America from Europe (though originating in Asia), is significantly reducing the number of trees. Resistant strains are starting to appear, however, and are being used in breeding programs to eventually restore and reforest affected areas.

In its high mountain habitat, Greast Basin bristlecone pine is subject to weathering from ice crystals and dust, particularly from the direction of the prevailing wind. On the side of the tree away from the wind, the individual continues to eke out an existence, but on the side of the tree facing the wind, the trunk tissue is subject to a “death by a hundred million cuts”. This abrasion over hundreds of years will first wear away the living tissue of the trunk and then begin work on polishing and sculpting the dead interior wood, as is shown in today's photograph.

Black cottonwood has previously been featured on BPotD here: Populus trichocarpa. Two resources to add to those listed there: the Silvics of North America treatment of Populus trichocarpa and GRIN's Populus balsamifera subsp. trichocarpa (a synonym; the previous BPotD touches on the naming issue).

This photograph was taken on the shores of Medicine Lake in Canada's Jasper National Park. “Medicine Lake” should actually be in quotes — it's not a true lake, as it only exists for part of the year. The in-flowing Maligne River backs up in this area for several months of the year due to the volume of glacial meltwater, forming the lake-like body. The water slowly drains via a series of sinkholes, travels through a cave system and then emerges 16km / 10miles downstream in Maligne Canyon. You can estimate the summer high-water mark from the band of vegetation-free shoreline.

Entomology / photography resource link: Via the Zooillogix weblog, mantis photographs by photographer Igor Siwanowicz. If you want to see more of Siwanowicz's work (and trust me, you want to), visit his photo.net gallery: Igor Siwanowicz.

Thank you again to Douglas Justice for both today's photograph and accompanying written entry. – Daniel.

Today's photo was taken at the Botanical Garden, but the tree from which the cone was taken grows some distance away on the UBC campus. John Worrall, whose thumb and forefinger can be seen in the photo, planted a seedling tree grown from seed he collected in the wild in California approximately 25 years ago. Worrall, Professor Emeritus of Forestry, is well known as a dendrologist and fierce tree advocate, and equally, for his guerrilla tree plantings around UBC.

Known as the bristlecone or Santa Lucia fir (it is found in the Santa Lucia Mountains), the campus tree is now close to 15m tall and is coning for the first time. Most authorities place this species in its own group (some place it in its own subgenus — Pseudotorreya), based upon its unique, long, sharp-pointed buds and needles, and extraordinary cone bracts. These stiffly curving squirrel guards extend 5 or 6 cm from the cone and are each supplied with a sticky gob of resin. Although this beautiful conifer has an extremely restricted range, its conservation status was assessed as a “lower risk” Lr/cd (lower risk, conservation dependent) on the IUCN Red List (version 2.3, 1994).

Abies species are often difficult subjects in gardens, most preferring deep soils and the cool conditions of mountain slopes. However, western North American, Pacific Slope conifers are adapted to relatively dry summer conditions, and the Californian species to an especially long, hot, dry summer regime. This specimen has probably done as well as it has because it's planted against a large brick building, facing south and out of the reach of irrigation.

The high elevation subalpine and montane forests of the Rocky Mountains often have Engelmann spruce as a major tree species in their composition. A distribution map illustrating the broad western North American distribution can be viewed via the USDA Forest Service's Silvics of North America entry on Picea engelmannii. Note that Engelmann spruce can also be found within the Coast-Cascade Mountains and some of the high-elevation areas between the two mountainous belts.

A second subspecies of Picea engelmannii is recognized, subspecies mexicana. It is known from populations in Mexico and (some say) the Chiricahua Mountains. The Gymnosperm Database's entry on Picea engelmannii suggests that subspecies mexicana is found in the USA, while the Flora of North America concludes otherwise.

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Thank you to Monika F (aka monika & manfred@Flickr) for contributing today's photograph (original | BPotD Flickr Pool). We're grateful once again, Monika.

European larch is native to higher altitudes of southern and southeastern Europe, extending as far east as Ukraine. Like all larches, it is a deciduous conifer, losing its needles annually. As with all conifers, I recommend visiting conifers.org for more information on the species and genus.

Thanks to Michael F of the UBC Forums for the identification and explanation of the oddball cone.

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Today's image is a scan from the John Davidson lantern slide archives here at UBC Botanical Garden. This photograph was likely taken in the 1900s or 1910s before Davidson immigrated to Canada, as the locale of the image is Hazlehead Park in Aberdeen, Scotland (Aberdeen was Davidson's home prior to Canada).

Monkey-puzzle trees are classified as vulnerable (VU B1+2c) by the IUCN Red List. Native to Chile and Argentina, logging (including illegal logging in national parks) is contributing to the decline of these intriguing trees in the wild.

Read more about Araucaria araucana via the exceptional Gymnosperm Database (including the ethnobotanical aspect) and the Enciclopedia de la Flora Chilena.

The attempt of blogging the expedition wasn't very successful – a combination of too-long days and consecutive nights in places without web access forced me off regular updates. Catching up then became an impossible task on the road, so I halted. I'll still do a few more posts about it this week, now that I'm back in the office.

Today's BPotD posting is a companion to this posting about the expedition. Great Basin bristlecone pine, according to the Gymnosperm Database, “is generally regarded as the longest-lived of all sexually reproducing, nonclonal species, with many individuals known to have ages exceeding 4000 years.” Although the oldest individuals are often thought to occur in California's White Mountains, the oldest of them all, Prometheus, was found on Wheeler Peak in the same population where this photograph was taken. Was found, I emphasize, because it was cut down to determine its age. The story of Prometheus, the Martyred One, is covered in-depth by Leonard Miller on his set of pages dedicated to the bristlecone pine.

Ancient living trees share their groves with the skeletons of trees that have died, like the one in today's photograph. Decay of dead trees is extremely slow due to a combination of wood quality and the dry, cold, high elevation habitat in which the groves occur.

Though protected in a number of locations throughout its distribution range in California, Nevada and Utah (areas in red), Pinus longaeva is IUCN-listed as vulnerable due to the fragmented and low area of occurrence, as well as a decline in the replacement of mature individuals.

BPotD is in brief entry mode on weekends and holidays from April through September. – Daniel

A thank you to Dr. Iain Taylor for contributing today's image from Vancouver, BC. Iain's had many roles with UBC Botanical Garden; he is currently helping the garden navigate some of its infrastructure projects through the intricacies of the university bureaucracy.

Iain photographed this handiwork of Bernard and Lorraine Portier a couple weeks ago (the excavation made the local news). I think it's fascinating to see the interwoven roots freed of the surrounding soil. This (former) deodar cedar was planted in 1958 by the mother of Mrs. Portier. Thank you to the family for the permission to share this with you.

A note to local residents: Darts Hill Garden Park in Surrey will be open to the public for two days: tomorrow and next Sunday (the open house also includes a plant sale). It's a beautiful garden, and public opportunities to visit it are rare, so do plan to visit if you've the time.