Continental Conifers

If you consider the term Continental conifers you wouldn't be wrong to include those trees native to The Continent, i.e. Europe. Or you could define it differently...as in trees native to earth's various continents, all seven of them. Sadly there are no conifers extant in Antarctica* – one of the seven – but the other six do contain cone-bearing species, and they include North America, South America, Australia, Asia, the Arctic and yes, The Continent (Europe) too. Conifers are placed in the Order Coniferales which includes pines, firs, spruces, cypresses etc. The Latin name comes from conus for “cone” and ferre meaning to “bear” or “carry,” and that from the Proto-Indo-European root bher, meaning “to bear” or “to bear children.”

*Antarctica wasn't always frigid and conifers used to exist there. One Araucaria species, known as the “Norfolk Island pine” (Araucaria heterophylla) is known from the fossil record. 52 million years ago, before South America and Antarctica split, Norfolk Island pines were part of a rainforest that ranged across Australasia and Antarctica and up up into Patagonia.

Picea abies

I grow trees (or shrubs) from the remaining six continental locations, so let's consider some in their geographical distribution. Picea abies, the “Norway spruce,” is by definition from the Continent (Europe), but know that its range extends from northern Greece into the Arctic Circle, and also eastward to Poland and the Urals, the mountain range that basically separates Europe from Asia. I have seen the species in Greece, looking somewhat stunted, but I have never been to the Arctic or the Urals.

Old Tjikko

Probably the most famous Picea abies is not one of the myriad of today's cultivars, but rather Old Tjikko, the 9,550-year-old tree from Dalarna Province, Sweden, which makes it older than any Bristlecone pine (P. longaeva). It stands only 16' tall, and if you want to nit-pick it is a clonal tree, meaning that it regenerates new trunks and branches rather than being an individual tree of great age. Old Tjikko, named after the discoverer's dog, is surrounded by 20 other spruces, all over 8,000 years old. Due to heavy snow at their location on Fulufjallet Mountain, branches are weighted to the ground where they can take root which is why it is a clonal tree, and carbon dating estimates the age. A tree can't be much older from this area because the last ice age receded around 10,000 years ago. I would love to visit Old T. but one has to take a pre-booked guided tour in summer. That's probably best, so some blonde Norwegian knucklehead doesn't carve his initials or profess his love for his girlfriend on the trunk.

Pinus pinaster

Pinus pinaster

An interesting European conifer, Pinus pinaster, is commonly known as the “Maritime pine” since it is native to the western Mediterranean region, and even extends to northern Africa. I don't grow it due to questionable hardiness, although I could keep one in the greenhouse I suppose. P. pinaster's canopy isn't particularly impressive, somewhat broad and colored light yellowish-green to bluish-green, but it sports the longest needles (in fascicles of two) of all European Pinus species. Due to straight trunks it is an important forestry tree in Europe, although it has become invasive in South Africa, Australia and Argentina. Besides timber, it is a source of turpentine. Ornamentally, the main event is the orange-brown to dark purple plating bark, but I suspect I would never see it as spectacular in the greenhouse compared with the outdoor-grown trunk photos above. Pinaster is Latin for “wild pine.”

Pinus canariensis

Pinus canariensis is endemic to the Canary Islands (Islas Kanarjas), a Spanish archipelago that is quite closer to Africa (Morocco - 62 miles or 100 km) than to Spain. So, though from Europe politically, I consider it part of the African continent. Like Pinus pinaster, the bark of the Canary Island pine is fissured into gray to reddish-brown plates, but to me the canopy of P. canariensis is more attractive than with P. pinaster because the foliage is a pretty, grass green. Alas, not hardy either.

Juniperus cedrus

Juniperus cedrus

I have written before about Juniperus cedrus – also from the Canary Islands – so I won't dwell on it much here. I had it early in my career, but lost it in the winter of the second year that it was planted out. Of course it died, and Rushforth in Conifers says, “In cultivation, it needs a warm sunny site, otherwise it is tender. Zone 9 [20 F].” A dozen years ago I acquired another clone of Juniperus cedrus and it has demonstrated greater hardiness, and even survived 5 degrees F a few years ago. It demonstrates that you can have significant variation within a species, and it's why I hate to provide hardiness ratings, as if I or anyone else is qualified to do so.

Widdringtonia schwarzii

Samuel Edward Widdrington

The genus Widdringtonia is in the Cupressaceae family and the evergreen is native to central and South Africa. I have seen most of the species in mild-area arboreta, but none have impressed me as much as W. schwarzii which comes from the Willowmore District in Cape Province. It forms a narrow tree when young, but grows up to 100' in the wild and the canopy eventually becomes quite broad. I've seen photos of old gnarled specimens with attractive reddish-gray bark. The genus name honors Edward Widdrington, a Royal Navy captain and conifer botanist who was active in the late 1700s and early 1800s. The specific epithet honors Friedrich Schwarz, a 20^th century cactus collector.

Afrocarpus usambarensis

Afrocarpus usambarensis

Afrocarpus is a genus of six species in the Podocarpaceae family, and it was formally classified by John Theodore Buchholz, a professor of botany at the University of Illinois, the same botanist responsible for the segregation of Sequoiadendron as a separate genus from Sequoia. A. usambarensis is an evergreen conifer native to Rwanda, The Congo and Tanzania, and it is dioecious with male and female cones borne on separate plants. One must wonder how a genus in the podocarp family wound up in central Africa. The answer is that it was present in the ancient super continent of Gondwana which broke apart into the continents/countries containing South America, Africa, India, Australia and Antarctica between 160 and 30 million years ago. Yes, wow, land-masses floating and smashing into each other...and I would love to have a time-lapse photographic documentation of those events. Scientific evidence suggests that Africa drifted north into a more hot and more dry environment where the Podocarpaceae survived and thrived in the cool highlands of eastern and southern Africa. We have earlier seen how the Araucariaceae (as in the Norfolk Island pine) drifted north to its present position, and all you need is a couple of dozen millions of years to accomplish the process.

Araucaria bidwillii

Araucaria bidwillii

An interesting conifer that is native to the Australian continent is Araucaria bidwillii. According to The Hillier Manual of Trees and Shrubs (2019), “A large tree in the wild, much smaller in cultivation in the British Isles, with a dome-shaped crown, with long-reaching branches off the main straight trunk.” This species was first described by Bidwill in 1843 and the type location is in the Bunya Mountains, hence the common name of “Bunya Bunya tree.” The mountains were very significant to the indigenous people, and it was an area of major gatherings which occurred when the nuts of the Bunya pine ripened, from December to March. These were the largest indigenous gatherings in all of Australia, but sadly the events terminated in 1902. Araucaria bidwillii is the sole species in Section Bunya, except fossils of closely-related Araucaria mirabilis can be found in Patagonia, which is further evidence of the Gondwana split.

Araucaria cunninghamii

Araucaria cunninghamii

Allan Cunningham

Araucaria cunninghamii is commonly known as the “Hoop pine,” and the scientific epithet honors the botanist/explorer Allan Cunningham who collected the first specimens in the 1820s. The “hoop” name refers to the rough-barked trunk with circular markings. There is another form, A.c. var. papuana, that is found in the mountains of Papua New Guinea, and a third, var. glauca, that occurs on Magnetic Island off the coast of Queensland. A. cunninghamii is planted as an ornamental and is an important source of timber, and in the past it was used as masts for sailing ships, as the wood is soft but tough. The continent's champion tree measures 121' tall (37m) while the tallest is 144' tall (44m) in the Bunya mountains. A “champion” tree combines height, trunk circumference and crown spread.

Callitris macleayana

Callitris preisii

Callitris preissii

The Australian genus Callitris is commonly called a “Cypress pine,” although it is in the Cupressaceae family and not a pine at all. I have grown a couple of species, C. macleayana and C. preissii, but don't have these non-hardy species anymore because I gave them away to California customer-friends. Both are attractive in a rugged way at a mature size, but frankly they didn't look like much at a smaller size in my greenhouse. Sometimes I grow a species for five or six years and then I have had my fill of it, especially the ones that are not hardy in Oregon. C. macleayana is commonly known as the Stringybark pine for obvious reasons, but it can grow up to 131' tall (40m). C. preissii is endemic to Rottnest Island, Australia, and it has many common names ,but the Noongar people know it as marro. These aborigines live in the southwest of Australia, and have done so for over 45,000 years. Wanju Wanju Kaartdijin Noongar means “Welcome to Noongar knowledge.” One important demonstration of knowledge is that C. preissii is used along the Murray River as a combined canoe pole and fish spear nearly 13' (4m) long. All of the above photos were taken in mild-area arboreta, and I've never seen any Callitris in the wild.

Araucaria angustifolia

Araucaria angustifolia

Araucaria angustifolia

Let's head now to South America from Australia, a distance of 9,483 miles (15,261 km), where we also find Araucaria. Besides the universally-known Araucaria araucana (the “Monkey Puzzle tree”), a lesser-known species is A. angustifolia, the “Brazilian Monkey Puzzle,” and it differs with narrower leaves. The epithet angustifolia is from Latin angustus meaning “narrow” and folium meaning “leaf.” According to Hillier it is endangered in the wild and rare in cultivation in the British Isles.

Podocarpus salignus

Also from South America is Podocarpus salignus, and according to Hillier, it's “A most attractive and elegant small tree or large shrub with drooping branches and long, narrow, bright grey-green leaves.” The evergreen is from southern Chile and is known as the “Willow-leaf podocarp.” Unfortunately it's not hardy for me, but I'd love to acquire one for the greenhouse. The above photo was taken in southern England and I envy their climate.

Abies religiosa

Abies religiosa

There are a great number of coniferous species from North America, and one of my favorites is the Mexican-Guatemalan Abies religiosa, the “Sacred Fir.” Though it is listed to USDA zone 8 (10F), I've had one in the collection for over 25 years, but it's difficult to photograph because the foliage is sooo dark green. The common name is due to its use as decoration in religious festivals, and to the indoctrinated the appearance of the needles along the stem resemble a cross. The fir was first described by Carl Kunth (1788-1850) but it was seen by my exploration heroes, the Europeans Humboldt and Bonpland before that (in the early 1800s).

Monarch butterflies in the Michoacan mountains

Twenty years ago I visited Mexico with my good friend R. Hatch, and one of my purposes – less so, his – was to venture into the Michoacán mountains to see the Abies religiosa forest, for that is where the Monarch butterflies congregate to overwinter and then mate. Wow – mating Monarchs! – it promised to be one of nature's greatest orgies, and I am pervert enough to want to voyeur. We arose early from Morelia – the state's capital city – and zoomed into the mountains to see the butterflies. Logging was evident, and habitat loss is one of the main threats to their survival. It was Hatch who prompted such an early start, and when we arrived at our destination it was barely light at 8:30 AM and there was frost upon the ground. It was cold; but after a half-mile walk we arrived at the area most populated by the winged creatures; we found masses lethargically sleeping upon the branches, with only a few fluttering about. At 5000-to-6000' elevation (I suppose) it was too early for the Monarchs to de-cling and become active, and since Hatch – not me – was anxious to press on I never did see them in full flutter, and I probably never will return.

The Pinophyta (known commonly as “conifers”) was estimated (in 1998) to contain 8 families, 68 genera and 629 living species...but I'm sure that numerous reclassifications in the past 22 years have skewed those figures. I suppose that the greatest number occur in the continent of Asia, but I've never done the counting. I read once that the greatest number of conifer species per a certain area of medium size was in California, and I thought – wait a minute! – I'll bet it is in Japan, not California. So, whatever the California number was, which I now forget, I went to my Hilliers Manual and counted those species native to Japan. It turns out that the California assertion was correct, but not by much.

Picea torano

Picea torano

Picea torano

In any case, let's consider one Asian conifer: Picea torano, previously known as P. polita, “from central Honshu, Japan, south to Shikoku and Kyushu” according to Rushforth in Conifers. Hillier (or the RHS) now contend that precedence insists upon P. torano (also hari momi) which is translated from Japanese as “tiger's tail” due to the viciously sharp needles...and my grafters can certainly attest to that unpleasant attribute. It is a beautiful, dense symmetrical species and I love its pitch-dripping cones. I have grown and sold P. torano for over 30 years and we propagate by grafting onto the “Norway spruce,” Picea abies. Rushforth is very paucus with P. torano information – and I wonder why – but he claims it is hardy to zone 6. That's a good guess, but I have a Michigan customer who repeatedly buys it and his customers garden in zone 5. Though it is a bitch to graft, the current-year's shoots are attractively blonde in color and the round buds are fascinating to me, very unlike any other spruce species. I wrote this last sentence from my couch at night, but the following morning I ventured out into the Upper Gardens to reconfirm my description, and yes, it is accurate.

Ginkgo biloba

Ginkgo biloba 'Saratoga'

Ok: I guess I have discussed all of the earth's continents...haven't I? Concerning conifers, do I have a favorite? Yes, of course I do – it is Ginkgo biloba – a sort-of-conifer according to many because it has deciduous leaves; but its botanic designation in the Coniferae is due to mobile sperm in its reproductive process. What?! – swimming seed?! – well, yes – that is in the definition.