thymeleaf speedwell (Veronica serpyllifolia)
Veronica serpyllifolia L. var. nummularioides Lecoq & Lamotte
Veronicastrum serpyllifolium (L.) Fourr.
Veronica serpyllifolia L. var. serpyllifolia
CONFIRMATION STATUS: Pending confirmation.
TAXONOMY: The currently accepted scientific name of thymeleaf
speedwell is Veronica serpyllifolia L. ssp. serpyllifolia.
NATIVE STATUS: Introduced, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS:
Habit: Thymeleaf speedwell is a rhizomatous, perennial herb with stems
that root at the nodes. Stems are 10 to 30 cm tall, branched and creeping
at the base, and glabrous or short-haired.
Leaves: Leaves are hairless or nearly hairless, elliptic to ovate, rounded
at both ends, opposite, and 8 to 25 mm long with smooth to weakly tooth-
ed margins. Lower leaves have short stalks and three veins that originate
from the leaf base, whereas upper leaves are sessile.
Flowers: Few to 40 flowers are grouped together in terminal racemes.
Flowers are stalked, irregularly four-lobed, 6 to 8 mm in diameter. The
petals are white to pale blue with pronounced darker blue lines, usually
on the upper petal, less so on the lateral petals, and faint or non-existent
on the lower petal. The lowest lobe of each flower is narrower than the
other lobes. Sepals are 2 to 5 mm long. Mature flower stalks are 4 to 6
mm long and are covered in short, light- colored, upward-curved hairs.
Upper bracts are narrowly oblong and longer than the flower stalks.
Fruit/Seeds: Capsules are hairy, heart-shaped, flattened, 2.5 to 4 mm
long, and wider than they are long with a 2 mm long style and numer-
ous seeds. Seeds are approximately 0.7 mm long.
Roots: The root system is fibrous and rhizomatous. Colonies of plants are often produced at favorable sites.
REGENERATION PROCESS: Thymeleaf speedwell propogates itself
by reseeding and and vegetatively by rhizomes and creeping stems that
root at the nodes. Most of the seeds of plants in the Veronica genus fall
to the ground relatively close to the parent plant. Seeds lack specialized
adaptations for dispersal; however, some seeds may be dispersed long
distances by water, wind, or animals. Seeds can be transported in mud
attached to shoes, clothing, vehicles, agricultural equipment, and con-
struction equipment. Seeds can likely survive ingestion by cattle and
probably other mammals.
HABITAT TYPES: Thymeleaf speedwell grows in moist, roadside
ditches, roadsides, and waste places. Habitats are usually associated
with anthropogenic (human induced) disturbances; areas of high human
frequency, such as roads and hiking trails, parking areas and playgrounds,
and grassy areas of parks are typical habitats for thymeleaf speedweel. In
addition, thymeleaf speedwell can be found in low areas along ponds,
rivers, and springs. As in other cases, the wet habitats are usually disturb-
ed and semi-shaded.
SITE CHARACTERISTICS: Thymeleaf speedwell prefers full sun to
light shade and moist to mesic conditions. Different kinds of soil are tol-
erated, including those that contain loam, clay, sand, or silt. It tends to
grow best in moist, heavy soil exposed to partial sunlight during the cool
rainy weather of spring.It does not compete well with other species.
SEASONAL DEVELOPMENT: The blooming period occurs from mid-
spring (April) to early summer (June).
GENERAL DISTRIBUTION: Thymeleaf speedwell is a species that is
widely dispersed, occurring from Georgia north through New England in-
to all the eastern provinces of Canada (even into Greenland). Less com-
mon along the Gulf Coast, it has not been reported from the southwest or
far lower Pacific Coast states. It occurs west through the Ohio Valley re-
gion and upper mid-west (California), but is generally not found in the
Rocky Mountain states. It reoccurs in the northwest states and can be
found in the Pacific Canadian provinces (British Columbia and Yukon)
SKY MEADOWS DISTRIBUTION: To be determined.
IMPORTANCE AND USES: Very little is specifically known about
floral-faunal relationship for this species. The flowers are cross-pollinat-
ed by flies and small bees (e.g., Syrphid flies, blow flies, and Halictid
bees). These insect obtain primarily nectar from the flowers. In limited
amounts, the foliage is not particularly toxic to vertebrate animals; it is
probably eaten by the cottontail rabbit, groundhog, and Canada goose.
The flat tiny seeds can cling to the feathers of birds, fur of mammals, and
shoes of humans; this method of locomotion helps to spread the seeds in-
to new areas.
Crooked Run Valley