Machaeranthera tanacetifolia
Encyclopedia
Machaeranthera tanacetifolia is a species of flowering plant in the aster family
known by the common names tansyleaf tansyaster and Tahoka daisy. It is native to northern Mexico and the southwestern and central United States, where it grows in several types of habitat. It is an annual or biennial herb growing one or more branching stems up to about 70 centimeters in maximum height. The multilobed leaves are up to 12 centimeters long. The inflorescence
bears one or more flower heads
lined with spreading or curling, pointed phyllaries
. The head has a center of many yellow disc florets and a fringe of many lavender to purple ray florets each 1 to 2 centimeters long. The fruit is a flat achene
about a centimeter long including the pappus
.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by the common names tansyleaf tansyaster and Tahoka daisy. It is native to northern Mexico and the southwestern and central United States, where it grows in several types of habitat. It is an annual or biennial herb growing one or more branching stems up to about 70 centimeters in maximum height. The multilobed leaves are up to 12 centimeters long. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
bears one or more flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
lined with spreading or curling, pointed phyllaries
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
. The head has a center of many yellow disc florets and a fringe of many lavender to purple ray florets each 1 to 2 centimeters long. The fruit is a flat achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
about a centimeter long including the pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
.