Tuesday, October 25, 2011

Ionactis (Aster) linariifolius: The Narrow Leaved Aster

This is becoming one of my favorite fall flowering plants among the native flora of Ohio and commands interest on all fronts; being botanically, ecologically, and horticulturally engaging.  As I add more posts to this blog, this phrase is likely to be constantly repeated.  The Aster family (Asteraceae), arguably the largest family of flowering plants in the world, has among there ranks some of the most fascinating, beautiful, and highly derived plant forms to be witnessed.  Perhaps the most curious of all belong to the genus Mutisia, a group of suffrutescent or woody species that typically inhabit high elevations in the Andes mountains, with a particularly large presence in Chile.  Ionactis (Aster) is not one of these species, but if you carefully compare them, it is hard to mistake that there is something eerily similar in appearance between Ionactis linariifolius and  Mutisia linearifolia.  Considering that these species shared a relatively recent common ancestor,  it is reasonable to assume convergent evolution played a role here, but that is not the topic of my present muse.  Mutisia (and a great many other Andean alpine endemics) are notoriously intractable in cultivation.  In the ease of cultivation category, Ionactis lies at the opposite end of this spectrum, and makes an easy to grow plant given the proper conditions.  


The verdant, mound-forming habit of Ionactis (Aster) linariifolius in late summer

Formerly Aster linariifolius, this species has a unique and rugged charm not present  in some other genera of native asters.  This species named is derived from the densely pubescent narrow, linear leaves that are stiff to the touch and remiscent of conifer needles.  The flowers can appear from late summer well into autumn, are born one per stem, and can range from white, to pale lavender,  to light purple .  Flowering can last well into November and seeds do not mature until late in the season.  The first year I tried to collect seed was in Late October, and still too early!  Around mid-November is more appropriate.  This species is also unique in forming woody(suffruticose) growth at the base, much in the same fashion as some Mutisia species. 

Another reason this is one of my favorites plants is because of where you can find it growing.  In Ohio this species is rare; it occurs on uplands with Pinus virginiana, Viola pedata (bicolor form), Antennaria spp., Iris verna and other acid soil loving plants.  On the cumberland plateau, and specifically along the Big South Fork River in Southern Kentucky this species occurs in a completely different and utterly unique habitat.  The boulder bars that have formed along the river harbors one of the most unique plants communities to be found in the eatern United States.  Here, Ionactis grows in hummocks of peaty sand between large boulders.  These hummocks support several plants species; Phlox amoena Liatris microcephala, Solidago arenicola, Conradina verticillataAndropogon gerardii, and Baptisia australis.  Along the Cheat River in eastern West Virginia, the boulder bars persist, but there is a slightly different assemblage; Marshallia grandiflora, Trauvetteria caroliniensis, and Andropogon gerardii can be found here, but there are none of the cumberland plateau endemics.  So whats the point of all this?  Ionactis is a fantastic indicator plant, and finding it may lead to finding other rare species of plants.  


 Ionactis (Aster) linariifolius nestled into a sandy hummock with Marshallia grandiflora in West Virginia

I have only been growing Ionactis in the garden for a couple of years.  My material orginiates from southern Ohio and appears to be quite hardy.  Although the parent plants are growing on a steep grade below a dry pine woods, three seedlings placed in moist sand/peat bed are thriving and have formed dense, rounded mounds 30 cm tall and 40 cmm wide.  I now have many more seedlings of this species growing.  It will be interesting to assess the differences in flower color, plant habit and adaptation to average garden conditions over the coming years.  More on this to come…




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