''Tetradymia stenolepis'' is a species of flowering plant in the
aster family known by the common name Mojave cottonthorn.
It is native to the deserts around the intersection of
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
,
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
, and eastern
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, where it grows in woodland and scrub habitat on sandy and gravelly substrates. It is a bushy
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
with many branches coated in woolly white fibers and growing to a maximum height just over a meter. The narrow leaves are 2 or 3 centimeters long and harden into straight, sharp spines. Clusters of woolly leaves grow near the spines. The
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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
bears up to 7
flower heads
A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...
which are each enveloped in four or five woolly
phyllaries
In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one or ...
. Each head contains up to four or five tubular yellow flowers each around a centimeter long. The fruit is a hairy
achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...
which may be nearly 2 centimeters long, including its
pappus of long bristles.
References
External links
Jepson Manual TreatmentFlora of North AmericaPhoto gallery
Senecioneae
Flora of Arizona
Flora of California
Flora of Nevada
{{Senecioneae-stub