Conifers
April 14, 2008
Callitropsis macrocarpa
One housekeeping item before today's entry: if all goes well with my schedule, I'll be upgrading the software that runs BPotD tomorrow. I expect at least a few outages where the BPotD entries won't be accessible.
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).
Posted by Daniel Mosquin at 8:39 AM| Comments (9)
January 28, 2008
Pinus roxburghii
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.
Posted by Daniel Mosquin at 8:41 AM| Comments (7)
December 28, 2007
Taxodium distichum
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.
Posted by Daniel Mosquin at 8:26 AM| Comments (3)
December 25, 2007
Pinus wallichiana
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!
Posted by Daniel Mosquin at 1:00 AM| Comments (9)
December 21, 2007
Taiwania cryptomerioides
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).
Posted by Daniel Mosquin at 7:02 AM| Comments (9)
November 26, 2007
Pinus monticola
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.
Posted by Daniel Mosquin at 12:02 AM| Comments (9)
October 28, 2007
Pinus longaeva
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.
Posted by Daniel Mosquin at 9:01 AM| Comments (10)
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Botany Photo of the Day and all associated images are licensed under a Creative Commons License.
Botany Photo of the Day is a project of the UBC Botanical Garden and Centre for Plant Research, located in Vancouver, British Columbia Canada. UBC BGCPR is a department of the Faculty of Land and Food Systems within The University of British Columbia.