Larry Davis wrote: While trying to look up R heliophila alba I came upon a description of R pratincola from the Rose Annual vol 8 which says it is almost herbaceous. R. pratincola is also an old name for roses of this same arkansana group.
Greene = R. heliophila
Greene. Greene changed the name when he learned that "pratincola" had already been used for a European species. I think it is important to distinguish the various forms lumped together under R. arkansana
Porter because of their particular environmental adaptations. As Greene (1899) wrote: "Probably no botanist knowing, as I know, both the Illinois and Wisconsin prairies, and the valley of the Arkansas in Colorado, could be brought to entertain the notion that any species of rose could be common to the two. The latter is an arid and subsaline half-desert country, a region of cactaceous and salicorniaceous plants, probably about as different from the region of Rosa pratincola
as Arabia is from England; a consideration which does not seem to have entered the minds of our American rhodologists—if we have any—much less those of the European students of the genus."
Do you recall the country road where you saw the alba form? You can PM if you prefer not to tell it abroad. It might still be around 35 years later. For sure my local rose suckers, and late flowering shoots come from the base of the plant, from an underground stem. I took a photo and send to the RHA newsletter for an article on plant architecture. But I forget if it got in there or not.
I PM'd the address. I doubt that the area would be swarmed by mad rosarians, but if you happen to be in the area you get first dibs. I also indicated the area where I found a couple of red-flowered forms. The exact site is no longer there - on the slope of a railroad overpass (now gone). But maybe in the area.[/quote]
For seedlings maybe we can distinguish depending on whether shoots arise only from leaf AXILS or whether they are adventitiously popping up from below the location of the cotyledenary leaves. I'm thinking right now of a peculiar seedling that I have in the lab in a pot. Last week it shot out a horizontal shoot at ground surface which is now several inches long and still nearly horizontal. I'm fairly sure that the first true leaves were several inches up from where this came out. If it had stayed below-ground it would have looked like a sucker when it finally emerged. In fact one of its siblings, a Rosa laxa x R virginiana OP (from David Z) did exactly that in a pot outdoors in the fall.
I once had an odd seedling that seemed normal, until the tip abruptly went horizontal. I suspected insect damage, but saw no evidence. The shoot continued horizontally, and side-shoots grew out in the same fashion. Then another shoot from the seedling did the same thing. I have no pics and no explanation, since none of the possible parents grew at all like that. The only remote possibility was a bogus R. soulieana
I purchased from Ralph Moore. It looked more like a form of R. wichuraiana
, and was a relentless creeper. It insinuated its way through my zoysia lawn. I didn't even notice it until it was a few feet long, hidden in the grass.
There are too many degrees of variation to name definitely. I have given up any notion that there could be a "gene for stolons" vs. a "gene for rhizomes". The distinction apparently is not in stolon vs. rhizome, but in where the plant invests its self-preservation resources. A tough, winter hardy bush can send out horizontal, underground branches to expand its territory while maintaining its "home base". On the other hand, a different sort of plant can escape the ravages of winter (and of summer) by going underground, and sending up flowering shoots that survive for only a year or two.
Here are a couple of papers you might find interesting:
Studies on Subterranean Organs. I. Compositae of the Vicinity of Manhattan, Kansas.
Transactions of the Academy of Science of St. Louis, 9: 1-8 (1899)http://www.biodiversitylibrary.org/item ... 1/mode/1up
Studies on Subterranean Organs. II. Some Dicotyledonous Herbaceous Plants of Manhattan, Kansas.
Transactions of the Academy of Science of St. Louis, 10: 131-142 (1900)http://www.biodiversitylibrary.org/item ... 7/mode/1up