Friday, January 4, 2019

Striking Strobili

Abies firma 'Halgren'

A strobilus (plural: strobili) on a conifer is a structure (containing spores – sporangia) which arranges itself along the stem. Generally it is the woody female strobili that are commonly called "cones," and that's because they often present themselves with cone-like shapes. Human members of the American Conifer Society are more likely to be identified with round heads, nevertheless they are often referred to as "coneheads."

Cathaya argyrophylla

Male strobili (microstrobili) can be fascinating – or lead to hay fever – and often they are very colorful in spring. Whap the branches of a Cupressus or Pinus and you can send out a cloud of pollen, but if you're not there the wind will do it for you. The female cones (megastrobili) contain the ovules, and when fertilized by the pollen they become seeds...which lodge themselves within the cone scales. Members of the pine family (Pinaceae) have developed imbricate scales, that is they overlap each other like shingles on a roof. The scales on a pine cone or true fir cone can be arranged in a spiraling pattern where each cone consists of a pair of spirals with each one ascending upwards in opposite directions. The number of steps will often match a pair of Fibonacci* numbers.

*The Fibonacci sequence starts like this: 0,1,1,2,3,5,8,13,21... and so on forever. Each number is the sum of the two numbers that precede it.

Abies koreana 'Silberlocke'

I suppose if I have favorite female strobili it is on Abies koreana, and I love to watch them develop throughout the year. If you expose your children to the beauty and order in nature by simply studying a cone they will be less likely to become drug addicts and welfare recipients in the future. It's not only the cones that are fascinating, but so too are the forms and foliage colors of the cultivars, and I have far more A. koreana selections in my nursery than with any other Abies species. A. k. 'Cis', 'Ice Breaker' and 'Silberlocke' have gained the coveted RHS's Award of Garden Merit. It was the famous plant explorer E.H. Wilson who first described the Korean native in 1920 after his type collection in 1917 on Jeju Island (then known as Quelpaert Island) located just below South Korea's mainland.

Abies concolor 'Sherwood Blue'

Abies concolor was so-named because the foliage looks the same throughout its Rocky Mountain range (concolor, hence "one color"). When it comes to cultivars, however, foliage can range from gray to gold to silver-blue. The latter is well-represented by the striking 'Sherwood Blue' developed by the late Andy Sherwood of Oregon. In the November photo above you can see how the cones disintegrate, where half the seed bracts have already fallen to the ground leaving only the "spindles." All of the Abies do this I think: all of the cones develop in one year, and at this point there are only a few left intact, one plant of which I visited today: Abies forrestii var. georgei, named for the famous plant collector, George Forrest of Scotland.

Abies pindrow

One of my favorites of the "true firs" is Abies pindrow with its deliciously soft green foliage. I must have 7 or 8 good-sized specimens in the collection, my start coming from the famous Otto Solburger Arboretum only 15 miles away form my nursery. S. passed away long ago before I could meet him but he was a Christmas tree grower who also collected conifers from around the world. His son was a logger, and after the old man passed Logger-man thought he would improve the collection with his chainsaw. A "Norway spruce" and the one-and-only Abies pindrow were vying for space; Egads! The latter was edited as the greasy-plaid-shirt son felt the spruce was the more attractive with its Christmas-tree-shape. In spite of my love for A. pindrow, I can't find anything good to say about its cones – they are small and narrow and difficult to spot in the dense foliage. So, the beautiful pindrow doesn't show off with cones, just like the women I find most attractive don't bother with much jewelry or other additional adornment.

Picea orientalis 'Skylands'
Picea orientalis 'Aureospicata'

Picea orientalis 'Lemon Drop'

The female strobili on Picea orientalis are long and narrow. Young purplish cones ooze with pitch before opening, then summer then bake to an amber-brown before dropping...intact, unlike the disintegrating Abies. We have two large P. o. 'Aureospicata' which drop thousands of cones. Not so many seeds germinate naturally – only about 50 per year – but now and then we'll find a 2-year seedling with golden new growth like its parent. One of these we christened 'Lemon Drop', but it is too new to fully assess. But most ornamental on the parents are the crimson-red male strobili, and though small they are prolific. With a name like P. orientalis you might assume that the species is native to the Far East, but in fact its range is in northern Turkey and the Caucasus, because in Roman times that was the far east (from Latin oriens, "the east," or "the rising sun.").

Picea orientalis and Picea abies

I also grow one straight-species of Picea orientalis, of seedling origin, and it is planted next to a seedling Picea abies, both of which were planted as "first" trees in my empty garden so I could produce some garden height. I am reminded of Rushforth's comment in Conifers (about P. orientalis), "It deserves much wider planting, and has the grace and charm* so palpably missing from Norway spruce."

*[Hey, we now have a rare moment on the first day of 2019 when the sun is out. The photo above depicts P. orientalis on the left and P. abies (the Norway spruce) on the right. I definitely prefer P. orientalis over P. abies as does Rushforth, but I wouldn't describe either species as possessing any particular "grace or charm." My opinion is: Don't rush forth too surely with subjective praise in your comprehensive conifer gazetteer which is purportedly "scientific."]

Picea torano

Bernhard Koehne
Picea polita is the "Tigertail spruce" native to central and southern Japan, except that now we're supposed to call it P. torano per Bernhard Koehne (1848-1918), a German (Polish) botanist and dendrologist. Torano (from Toran wo) means "tiger's tail" in Japanese – not that it resembles one – but because the needles are viciously sharp. The male strobili are an attractive purple-red, and appear in Oregon in May. The female strobili are plump and ornamental, cream-green and dripping with pitch when young, then ripening to brown by fall. We used to grow P. torano in the field, and the year following harvest the digging jolt caused the trees to cone heavily, even when relatively small, and that was a delight for the retail customer.

Picea glauca 'Mac Gold'

The prolific cone-set after digging occurs with other species as well, particularly with Picea glauca. P. g. 'McConnal's Gold, AKA 'Mac Gold', is a wonderfully neat, compact upright selection with golden new growth in spring. The yellow shoots contrast well with the older, dark green foliage, and best of all is that it can thrive in full sun in Oregon. An important horticultural service provided by Buchholz Nursery is that we allow all trees to be grown a full year in pots to recover after digging. This means the specimen will produce the best, vibrant yellow growth the following spring, so in a sense we "nurse" the tree for our customers so it can sell immediately when they receive it. This practice is more costly for us, but it certainly encourages future sales. 'Mac Gold' was found growing in 1985, and Joe Stupka of Pulaski, PA is credited with the discovery.

Picea smithiana

Picea smithiana is the "West Himalayan spruce," native to the area from Afghanistan to west Nepal. I was impressed with it in the wild – some 25 years ago – for tall, narrow crowns on old trees, although younger specimens in cultivation tend to be almost as wide as tall. It is a beautiful spruce with its semi-pendulous branches, similar but different from "Brewer's Weeping spruce," Picea breweriana. P. smithiana is only hardy to USDA zone 6 (-10 degrees F) so I couldn't sell it to much of the country, but the main reason I discontinued production was because it attracted a pest moth that killed the tops. Now I see only one specimen and it is planted on neighboring property that I leased years ago. I drive past it three or four times per day so in a sense I still "own" it even though I don't farm that ground anymore.

Picea smithiana 'Pakistan'

The common name of Picea smithiana is "Morinda spruce," and that name is derived for its name in Nepali which refers to the pitch that drips from its female strobili, known as "the honey of flowers." The specific epithet honors James Edwards Smith, the gardener at Hopetoun House estate outside Edinburgh, Scotland. He grew the first seed brought to Europe in 1818, and a tree planted in 1824 can still be seen today.

Sequoiadendron cone

The term "pine" suffices for most of the public who don't know, or don't want to know what distinguishes various coniferous genera. So too, then, with "pine cones." I had a war with the neighborhood bully when I was a kid, and his stupid mother defended the brat when I beaned him with a Sequoiadendron strobilus and halted his aggression. I was called before the school principal and ordered to stop throwing pine cones.

Pinus parviflora 'Cleary'

Pinus parviflora 'Bonnie Bergman'
Pinus parviflora 'Arnold Arboretum Dwarf'

Anyway, let's consider the strobili of the true pines (Pinus). P. parviflora dwarves such as 'Kinpo' tend to have small female cones while the faster-growing cultivars such as 'Cleary' and 'Glauca' will display larger cones. The selection 'Arnold Arboretum Dwarf' displays cream-white male strobili which will poof pollen into the air if you bump into it in May. The male strobili on 'Bonnie Bergman', however, are maroon in color. It is easy to overlook the male pollen's contribution to plant interest when so much else is going on in the garden in spring, so maybe I am a voyeuristic pervert since I'm attracted to all of the trees' sexual expressions, but probably the orgiastic prude should stay out of the garden altogether if he is afraid to encounter reproduction in progress. I enjoy the lurid riot – the Rite of Spring – and, as my 12-year-old recently said, "Well, I wouldn't be here if you didn't do that stuff."

Pinus jeffreyi 

Pinus jeffreyi is a three-needled pine tree from western North America, but sadly it is considered a minor player in the flora compared to its cousin Pinus ponderosa, the latter which is the most widely-spread species in America. I love the squiggly microstrobili which pursue the macrostrobili of P. jeffreyi to do their business. A casual hike in the mid-elevation of western mountains will reveal the earnest efforts of the micros, but I suppose some pollen falls to lower elevation to mix with the P. ponderosa; and why not?: it's like a Scotsman producing children with an English woman, and really there's nothing unsemenly about it.

Pinus coulteri

Thomas Coulter
Pinus coulteri is barely hardy for me in Oregon since its range is in central and southern as far south as the north of Baja California. The male strobili possess no ornamental qualities – although they probably think of themselves as highly important – but the female participants are known to be the largest – not longest! – cones of the species: a single cone can weigh up to 5 lbs. (2.25 Kg). From a garden-ornamental point of view the Coulter pine is not very exciting and there are a lot of better choices for the landscape, but the massive cones make it worth planting where hardy (USDA zone 8). The specific name honors Thomas Coulter (1793-1843) who first collected the species. He was an Irish physician, botanist and explorer and it was the Scottish botanist David Don who bestowed the name.

Pinus attenuata

The cones of Pinus coulteri can persist on the tree for a number of years, but eventually they will fall intact, hence the "widow-maker" moniker, but I wonder if anyone really has been killed by a falling cone. Another pine with persistent cones, though not nearly as large, is Pinus attenuata, the "Knobcone pine." Its range is from southern Oregon to Baja California and it has the ability to thrive on poor soils. As with P. coulteri, P. attenuata has needles in fascicles of three. The strobili are often bunched at the branch, where maybe as many as six will gather. What is most fascinating is that the cones can remain closed for many years (up to 30) until a fire opens them and allows release of the seeds. P. attenuata might be found in a few arboreta in America and Europe, but there's absolutely no reason the scrappy species would be used in a landscape; still it's fun to drive old mountain roads in the evening and see the coned branches as silhouette in the dusky sky. The specific name is from Latin attenuatus for "pointed" in reference to the cone scales. It was first named by author George Gordon in The Pinetum (in 1858) as Pinus tuberculata, but I guess not "formally" enough, as it was changed to P. attenuata by John Lemmon in 1892 when he officially described it.
Cedrus deodara

Cedrus deodara 'Shalimar'
Deodar lumber

Cedrus deodara is the "Himalayan cedar" and it usually occurs between 5,000' to 10,000' in the foothills. I have begun a number of treks to higher elevations where one passes a solitary or a few old specimens at the trailhead, and I guess we're lucky they weren't cut down a century before. Perhaps they were spared for being "divine" because the Sanskrit name devadaru means "wood of the gods." (Deva = "god" and daru = "wood and tree"). Still, I have seen houses made from deodar wood and I also stayed on a houseboat in Srinagar, Kashmir built from the deodar wood. Female strobili are barrel-shaped and sit atop the branches, and on the same tree male flowers dangle like insect larvae with their cream-yellow color. On older specimens the male strobili can literally cover the ground.

Larix kaempferi 'Diana'

Larix kaempferi 'Wolterdingen'

J.G. Veitch

The "Japanese larch," Larix kaempferi (formerly L. leptolepis) is native to a small area of central Honshu, and it was introduced to England in 1861 by J.G. Veitch. There are a number of cultivars ranging from fast-growing upright trees to congested dwarves. 'Diana' was discovered in Germany in the 1970's growing in a reforested plantation, and it features gracefully contorted branches. 'Wolterdingen' is a bun with blue-green foliage that turns orange-yellow in autumn. It was found in 1970 in a park in Wolterdingen, Germany.

Larix kaempferi 'Paper Lanterns'

Don Howse
Larix kaempferi 'Paper Lanterns' is more dubious as a cultivar. It was selected in the 1980's by Edsal Wood of Oregon because the original seedling tended to cone heavily. I'm not sure if that characteristic is inherent in the plant or if the coning is culturally induced. Any conifer under stress, for example, is liable to produce a lot of cones. I saw the original at the arboretum of Porterhowse Farms, where owner Don Howse named and introduced it, and indeed it was loaded with strobili. It is no longer in production at my nursery because I can grow trees to 10' tall without a single cone, but I've never put one in the ground to see what happens. Maybe it's worth growing anyway for its narrow form, at least when young.

Pseudolarix amabilis

Pseudolarix amabilis in fall

Robert Fortune
More interesting for me than the Larix genus is Pseudolarix amabilis, a monotypic genus with male and female strobili borne on the same tree. It was introduced by Robert Fortune (of tea-stealing fame) in 1852 from eastern China. The specific epithet amabilis is Latin for "lovely" or "beautiful," and certainly the fresh spring foliage is most lush. As with the true larch, Pseudolarix is deciduous so the landscape is blessed with a clear golden-orange in autumn. I had never seen cones on Pseudolarix – and I suppose they would resemble those of Larix – until I walked past my original specimen in the Blue Forest one day and was shocked to find artichokes attached to the tree! I had missed noticing them all spring and summer, so my first encounter was when they had turned brown in autumn, and isn't horticulture fun?

The origin of the word strobulus is from Greek strobilos for "pine cone," or it can also mean a "whirlwind" or a "whirling dance." Seth and I have produced hundreds of Flora Wonder Blogs over the years, and I have characterized them before as "wandering narratives." But maybe more accurately they are "whirling dances" with Flora and I going round and around.

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