Chaenactis macrantha
Encyclopedia
Chaenactis macrantha is a species of flowering plant in the daisy family
known by the common names bighead dustymaiden and Mojave pincushion. It is native to the Great Basin
and the southwestern deserts of the United States, where it grows in dry, open habitat with gravelly, sandy soils, often calcareous
or alkaline in nature. It is an annual herb growing one or more branching stems to 30 or 35 centimeters in maximum height. The leaves are a few centimeters long and divided into many lobes. The inflorescence
bears one or more flower heads
on long peduncles
. The flower head is lined with woolly phyllaries
which have recurved tips. The head contains many white or pink-tinted flowers which open at night. The fruit is an 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 bighead dustymaiden and Mojave pincushion. It is native to the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...
and the southwestern deserts of the United States, where it grows in dry, open habitat with gravelly, sandy soils, often calcareous
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
or alkaline in nature. It is an annual herb growing one or more branching stems to 30 or 35 centimeters in maximum height. The leaves are a few centimeters long and divided into many lobes. 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....
on long peduncles
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
. The flower head is lined with woolly 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...
which have recurved tips. The head contains many white or pink-tinted flowers which open at night. The fruit is an 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...
.