Hecastocleis
Encyclopedia
Hecastocleis is a monotypic genus of plants in the daisy family
containing the single species Hecastocleis shockleyi, which is known by the common name prickleleaf. This plant is native to the desert mountains and plains of eastern California
and western Nevada
, where it grows on arid, rocky slopes and flats.
At the end of stem branches are solitary flower heads
, each enclosed between flat, oval-shaped, sharply toothed, leaflike, pale yellow bract
s. Between the bracts are the flower parts, which are pinkish when new and open into a greenish-yellow corolla. The fruit is a cylindrical achene
.
). Botanists at least as early as Asa Gray
(in 1882) remarked on its distinctiveness; it appears to have no close relatives within the aster family.
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...
containing the single species Hecastocleis shockleyi, which is known by the common name prickleleaf. This plant is native to the desert mountains and plains of eastern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and western Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, where it grows on arid, rocky slopes and flats.
Description
This is a low, brambly shrub producing a tangle of stiff, branching stems reaching heights between 40 and 70 centimeters. The stems have sparse glandular hairs and are lined with small pointed green leaves with a row of widely-spaced spines along each edge. As the leaf dries and its flesh falls away, the spines remain as hard prickles.At the end of stem branches are solitary flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
, each enclosed between flat, oval-shaped, sharply toothed, leaflike, pale yellow bract
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...
s. Between the bracts are the flower parts, which are pinkish when new and open into a greenish-yellow corolla. The fruit is a cylindrical achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
.
Classification
Hecastocleis shockleyi is the only species in the subfamily Hecastocleidoideae of the aster family (AsteraceaeAsteraceae
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...
). Botanists at least as early as Asa Gray
Asa Gray
-References:*Asa Gray. Dictionary of American Biography. American Council of Learned Societies, 1928–1936.*Asa Gray. Encyclopedia of World Biography, 2nd ed. 17 Vols. Gale Research, 1998.*Asa Gray. Plant Sciences. 4 vols. Macmillan Reference USA, 2001....
(in 1882) remarked on its distinctiveness; it appears to have no close relatives within the aster family.