38 Nebraskaland • August-September 2022
s their name implies, each
dayfl ower blossom is fl eeting.
New fl owers that open to greet
the rising sun close about noon
and wither by dusk. The lovely blue
fl owers are as delicate as they are
short-lived. When rubbed between
one's fi ngers, their petals quickly
disintegrate into a watery ooze.
Belonging to the spiderwort family
(Commelinaceae), two dayfl ower
species, both growing up to a foot tall,
inhabit Nebraska. Slender dayfl ower
(Commelina erecta) is a wide-ranging
perennial native to the Americas,
Africa and western Asia. They grow
alone or in loose clusters in sand
prairies in the western half of our
state, including the Sandhills. Oddly,
the plant is absent from apparently
suitable, sandy habitats in eastern
Nebraska.
Common dayfl ower (C. communis),
native to Asia, was introduced to North
America, likely as an ornamental, and
fi rst collected in Nebraska in 1905.
Limited to the eastern half of the state,
the sprawling annual is mainly a yard
and garden weed in clay to somewhat
sandy soils. The plant rapidly spreads
by rooting from nodes on its reclining
stems and, in infested gardens, can
form dense tangles among summer
crops.
Characteristic of the spiderwort
family, dayfl owers have distinct,
parallel veins running the length of
their leaves. Common dayfl ower leaves
are broadly lance-shaped and hairless,
while slender dayfl ower leaves are
narrowly lance-shaped and somewhat
hairy. Both species' fl ower heads are
hidden within a wide, folded, leafy
bract from which individual fl owers
emerge throughout the summer and
into early autumn.
Commelina fl owers have two bright-
blue, showy petals and a third petal
that is small and translucent or
sometimes absent. When present, it
sits below the two showy petals.
These highly-modifi ed fl owers are
designed for pollination by mid-sized
bees and fl ies. The fl owers contain no
sweet-scented nectar to attract and
reward pollinating insects. Instead,
the vivid blue petals catch the eye
of pollinators, while the four yellow,
cross-shaped anthers draw them
into the fl ower. In most plants, these
anthers contain a rich meal of pollen,
but in dayfl owers they contain none.
While fruitlessly probing the
infertile, yellow anthers, the insects'
abdomen fl anks are dabbed with pollen
from two blue, fertile anthers found at
the tips of long fi laments that extend
A
Slender dayfl ower blooms in a Sandhills prairie in Brown County. The small,
translucent third petal is visible below the blue petals.
Deceptive Dayfl owers
Story and photos by Gerry Steinauer, Botanist
