Friday, March 29, 2013

Bi-hemisphaeric twins: re-uniting Laurasia!

Trollius laxus v. laxus at Denver Botanic Gardens
It will be a few months before our native globeflower begins to bloom in the high Rockies--but this, it's eastern cousin always blooms in April. Trollius are widespread in the Circumboreal, subalpine regions of both Eurasia and North America--but this taxon seems to have a very similar cousin in the Dzungarian and Tian Shan Mountains of Central Asia.

Trollius dzungharicus in the Tian Shan Mts., Kazakhstan
 Although the more "typical" globeflowers with bright orange, globular heads occur in both Tian Shan and Altai Mountains, this soft yellow form is found sparingly as well--much more reminiscent of our American species.
Saxifraga flagellaris on the Tian Shan above Almaty, Kazakhstan

You can imagine my surprise when I found this whipcord saxifrage, which looks almost identical to what one finds twelve time zones away in the Colorado Rockies, growing in almost the same sorts of conditions!

                                             Saxifraga flagellaris (Colorado form) in a trough

 I actually managed to grow this in my garden--or trough rather: this is our native form of Saxifraga flagellaris--which looks identical to its Asian cousin.

Dryas octopetala on Horseshoe Mt., Colorado
Mountain Avens or Dryad is universal in tundra throughout much of the hemisphere: although they have been classed as different spedcies, or at least different subspecies, I find these two kinds almost indistinguishable.

Dryas oxydonta on the Tian Shan

This is the brilliant blue alpine geranium of the Tian Shan. It has an electric blue flower...
Geranium regelii on the Tian Shan, Kazakhstan
 Here is a compact form of the widespread meadow geranium (G. pratense) from the summits of the Tian Shan. Although superficially the dissimilar from the Pink American below--they are nevertheless related and classic examples of a Holarctic group of plants. Yes, I know there are a few geraniums in the Southern Hemisphere--they don't count because they are really different and don't fit into my grand scheme of things!

Geranium fremontii on South Park, Colorado
 Some botanists have lumped this with Geranium caespitosum. But not me! I still call this Geranium fremontii, named for the most restless and peripatetic of Western explorers...

Gentiana algida in Colorado
Gentiana algida was once known as G. romanzovii--honoring a Russian Botanist. The Eurasian manifestation seems to be a tad yellower (below) but I suspect they are equally intractable in cultivation!

Gentiana algida in the Altai Mts. of Kazakhstan
There are, of course, dozens of androsaces in the Chamaejasme section that look virtually identical: here with the rather local Colorado subspecies shown first, and the Kazakh cousin next.
Androsace chamaejasme v. carinata on Pikes Peak
The central yellow spot turns red on the American one as seen below in the Asian species.
Androsace akbaitralensis on the Tian Shan, Kazakhstan
Primula is a huge genus centered on the Himalayas: there are only a handful of species in Central Asia, and likewise in North America, but these are uncannily similar to one another
Primula xanthobasis on the Mongolian Altai Mountains
The Nivalid section of the genus Primula is apparently not that closely related to the Parryi Section of North America, but they are remarkably similar in habit and habitat: the one above is likely to be as hard to grow as its look-alike cousin, P. parryi that occurs over much of the Southern Rockies and intermkountain region.

Primula ellisiae (from New Mexico) in my trough garden
This beautiful endemic of central New Mexico has turned out to be quite easily grown in gardens--every bit as lovely as its fussier cousins.

Primula specuicola near Moab, April
There is a strong family resemblance among all the Aleuritia secion (once more graphically called "the Farinosae" for their flour like farina on the leaves. The one above grows on moist seeps in the canyonlands.  

Primula algida on the Tian Shan mountains, Kazakhstan
This one occurs above treeline over much of Asia.

Angelica turkestanica on the Tian Shan mts., Kazakhstan
Central Asia boasts a miniature Angelica that grows above treeline. It seems to be almost indistinguishable with its American equivalent below.
Angelica grayi on Horseshoe Mt., Colorado
Named for Asa Gray, the American twin is seen here growing on an almost identical alpine scree habitat. Of course, Asa Gray was the first on to note the parallels between East Asian and Southeastern American flora--but these circumboreal alpines are even more pronounced in their similarities and point to a time when their ancestors were single species spread over a single continent--Laurasia--that has now been split between Eurasia and America. I say it's high time to reunite these continents in our gardens at least, don't you agree?

The list of twins such as this could go on for hundreds of pages and not begin to exhaust the botanical twins that can be found in the Continental Western United States and then again on its steppe-sister climates of Central Asia....each year I suddenly notice a new brace of these, and am glad to be able share this!


  1. Is there a monograph or survey of the genus Primulacea ? Several years ago researching the poetry of an early American writer; I tried to establish the Primrose to which he referred, but was unable to find much beyond several old English reference to the way they grew species familiar to them.
    At the time, I recall trying to contact the defunct Primrose Society and didn't get very far there, either.
    It would be a breath of fresh air to appreciate the origin, discovery ( some of which you mention here ) and development of the various species

  2. the mention of wild Primulas awoke my interest but I should have looked before I leaped; there is a Timber Press book " Primula " and the Primula Society seems to have resurrected itself; so I've answered my own questions

  3. Dear Stephen, I'm sorry I did not see your messages: I was traveling when you posted and hadn't checked my blog. There is a Primula monograph by Josef Halda--I can provde you with one if you email me your address.



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