Description:
This herbaceous plant is a summer annual (in Illinois) that forms a low
rosette during the spring, but by summer it bolts to become 1-4' tall.
A typical plant is unbranched below and branched above with ascending
lateral stems. The stems are light green to light yellowish tan,
terete, glabrous, and stiff. Alternate leaves occur at intervals along
these stems. These leaves are 2-6" long, ½-2" across, and stiff;
they are lanceolate, lanceolate-oblong, ovate, or ovate-oblong in
shape. The leaf bases are sessile or they clasp the stems. Leaf margins
are mostly smooth (entire) with scattered yellow spines, although
lower leaf margins are sometimes spineless and slightly dentate
(although in some uncommon cultivars, all leaves may be spineless).
Both the upper and lower surfaces of the leaves are dark green and
glabrous; minute pubescence may occur along the lower surfaces of the
central leaf veins.
Each upper stem terminates in 1-5 flowerheads. The
flowerheads of each branch are usually clustered together on short
peduncles. Each flowerhead is ¾-1½" across (excluding the outer
phyllaries), consisting of 20-100 disk florets. These florets are ¾-1"
in length, although their bases are hidden from view. The corollas of
these florets are yellow to red (rarely white), narrowly cylindrical
below, and 5-lobed above; these lobes are linear in shape and
spreading. The styles are strongly exerted from the corollas. Around
the base of the flowerhead, there are several outer phyllaries (floral
bracts) up to 1½" long that are widely spreading and stiff; they are
elliptic or lanceolate in shape, while their margins are smooth
(entire) with scattered yellow spines. The surfaces of these outer
bracts are dark green and glabrous. The inner phyllaries are mostly
erect and appressed together; they are light green, ovate or lanceolate
in shape, and covered with appressed hairs. The margins of the inner
phyllaries are mostly smooth (entire) and ciliate, although their tips
are spiny. However, in some uncommon cultivars, both outer and inner
phyllaries are spineless. The blooming period occurs from mid-spring
into the fall (in Illinois), lasting about 1-3 months. Afterwards,
fertile florets are replaced by achenes. The achenes are 6-8 mm. long,
white or light brown, oblanceoloid in shape, bluntly 4-angled, and
often longitudinally striped. Usually the apices of these achenes lack
tufts of hair, although in some uncommon cultivars
short stiff bristles are present. The root system consists of a stout
taproot up to 3-4' long and some lateral roots. This plant reproduces
by reseeding itself.
Cultivation: Safflower adapts to full
sun, mesic to dry conditions, and various kinds of soil, including
those that contain loam, sandy loam, or clay-loam. It prefers cool to
warm temperatures while in the rosette stage, and warm to hot
temperatures after it bolts (a warm-temperate zone with long summer
days, a long growing season, and adequate rainfall prior to the
blooming period). In areas with high humidity or cool weather during
the summer, this plant is vulnerable to a variety of fungal disease
organisms. Because of the deep taproot, resistance to heat and drought
is excellent.
Range
& Habitat:
The non-native Safflower
uncommonly naturalizes in Illinois, occurring in Champaign County (see
Distribution
Map).
However, the presence of this species within the
state is probably under-reported. Because of its
preference for areas with relatively low humidity, Safflower is
cultivated primarily in the western half of the United States, where it
more frequently naturalizes. In the eastern half of the United States
(including Illinois), naturalized plants are typically found around
bird feeders as Safflower is sometimes used as a source of bird seed.
Naturalized plants can occur after birds inadvertently drop the seeds,
or spill the seeds from a bird feeder. As a result, typically habitats
in Illinois are unmowed areas around bird feeders, including vegetable
gardens, flowerbeds, open spaces near shrubbery, and edges of yards.
However, these naturalized plants rarely persist from one year to the
next. Safflower was introduced into the United States during the early
20th century as an agricultural crop (as a source of vegetable oil and
a dye for clothing or food). This plant is probably native to the
eastern Mediterranean region and parts of southern and central Asia,
where it has been cultivated for thousands of years.
Faunal
Associations: Little specific information is available for
the
floral-faunal relationships of Safflower in North America. The flowers
are cross-pollinated by bumblebees, honeybees, other
long-tongued
bees, and probably other insects with long mouth parts (e.g.,
butterflies & skippers). However, in the absence of
cross-pollination, the flowers are self-fertile. Seed bugs (Lygus),
aphids, leafhoppers,
thrips, wireworms, and the larvae of some moths are reported to feed
destructively on Safflower. Among vertebrate animals, some songbirds
(e.g., Cardinals) and probably upland gamebrids feed on the seeds,
which are sometimes used as a source of food in bird feeders. Prior to
the blooming period, the foliage of Safflower is reportedly edible to
sheep and, to a lesser extent, cattle. The suitability of the
foliage as a source of forage depends in part on its level of
spininess; this varies with different cultivars.
Photographic
Location: A mulched bed near some shrubbery at the Anita
Purves Nature Center in Urbana, Illinois.
Comments: Safflower is grown primarily as an agricultural
crop in the
western half of the United States and other parts of the world. The
flowerheads are a source of red and yellow dyes for clothing and food
(now largely replaced by synthetic dyes), while vegetable oil is
derived from its seeds. Safflower oil is high in oleic and linoleic
fatty acids, and it is used as a source for cooking oil, salad oil,
industrial oil, biodiesel fuel, margarine, soap, cosmetics, oil-based
paints, and varnishes. Roasted or fried hulled seeds are edible to
humans, while unhulled raw seeds are used as a source of food for
birds. Young foliage and meal from processed seeds are edible to
livestock (e.g., cattle & sheep). The primary advantage of
Safflower over other agricultural crops is its ability to adapt to hot
dry climates. Because of the spines on its foliage and floral bracts,
Safflower resembles thistles (
Cirsium
spp.,
Carduus
spp.), but the
corollas of its flowerheads are yellow to red, rather than pink or
purple. Unlike thistles, the achenes of Safflower lack tufts
of hair at their apices, except for some uncommon cultivars
that have achenes with short bristles. In addition, the widely
spreading and spiny floral bracts of Safflower have a distinctive
appearance.