Rock Garden Quarterly Summer 2012 - (Page 226)

Viola pedata is extremely variable in flower color, flower form, plant height and leaf shape. Such variation is unusual within a violet species and is discussed below. Flowers exhibit wide diversity between colonies or even between single plants. Stemless plants arise from stout, vertical rhizomes. Branching of these rhizomes can result in multi-crowned plants. Its roots are thick with fine rootlets. Adventitious shoots can produce new plantlets from the roots if the growing crown is damaged. The stipules are adnate to the base of the petiole for half the length of the stipule, their margins being both fimbriate and ciliate. “Pedata” does not mean “divided like a bird’s foot” as is often written. The meaning of the word “pedata” in Stearn’s Botanical Latin is “palmate, but with the lateral lobes or divisions themselves divided.” However, in reality leaf shapes are highly variable in the number and width of the lobes, and the presence or absence and depth of the primary or secondary divisions. Plants often produce two types of leaves during the growing season. At flowering time glossy new leaves are small with wide leaf lobes, but leaves produced for the hot dry summer months may have much narrower, longer divisions reducing leaf surface area and hence evaporation. In the fall, the plants revert to producing small leaves with wider lobes. Fine cilia occur on the upper leaf surface on both the veins and lamina and on the margins, but the lower leaf surface is glabrous. The ciliate winged petiole margin is curled inwards. There is a prominent gland on the tip of each leaf segment or lobe, also one large gland in the axil between segments. This characteristic is also seen with V. pedatifida but not V. beckwithii both of which possess glands on the segment tips. Large flowers measure up to four centimetres across (one and a half inches) but can be smaller. The face of the flower is flat with a shallow throat from which the style projects prominently, surrounded by orange anther extensions. On the inside of the lateral petals there are no guidelines and no hairs. Petals can be round or narrow. The two upper petals of the bicolored flower form are dark velvety blackpurple, often reflexed and sometimes twisted back to back. The three lowest petals are lilac, or unusually, purple spotted or streaked, and very rarely white. Colors of the concolorous flower form range from pale blue through violet to deepest lilac, slate blue, almost white to pure white without purple guidelines, and rarely, pink. They can be with or without a central white eye and with variable patterns of veining on the lowest petal. The spur is dark purple, 1.5 mm long and 2.5 mm wide, but flat in section. Flowers have no perfume. Unlike most other violets in North America, this species propagates only from open pollinated flowers (no cleistogamous pods). A study of Viola pedata by Becker and Ewart (1990) showed that cross-pollinations resulted in significantly greater quantities of seed than did self-pollinations, 226 Rock Garden Quarterly Vol. 70 (3)

Table of Contents for the Digital Edition of Rock Garden Quarterly Summer 2012

Digital Quarterly
Expanding Panayoti's Axioms
Photo Contest 2012
Photographing Alpine Plants: A Landscape Point of View
NARGS 2013 Election Timetable
Rock Gardening from Scratch - Seeds
Kim Blaxland and the Violets of North America
Viola pedata
Violas, Kim, and Us - A Celebration
Cooking Native Japanese Plants
Carl Gehenio Memorial Trough Show
Fire in the Hole: Phlox across Colorado
Rebuilding a Rock Garden in Pittsburgh
A Remarkable Garden: David Douglas and the Shrub-steppe of the Columbia Plateau
Bookshelf - Reviews
Swedish Dreams
Treasurer's Report
Bulletin Board
2012 - Eastern Study Weekend: October, Pittsburgh

Rock Garden Quarterly Summer 2012