Zanthoxylum parvum
Encyclopedia
Zanthoxylum parvum is nested within the family Rutaceae
. It is native to the mountains of Trans-Pecos
Texas
in Brewster
and Jeff Davis
counties.
plant. It is a dioecious
shrub and can grow up to 2 m tall. Stems have erect prickles, sometimes curved, which occur either solitary or paired; they range from 4-13mm long. Zanthoxylem parvum are imparapinnate with alternate leaves and average about 7–13 leaflets. The rachis
and petioles
are not winged.
Leaflets are opposite, usually oval shaped with a tapering point or sometimes ovate or lanceolate; the leaflets range from 6–16(−35) mm long and 11–18 mm wide with an obtuse apex and a triangular attaching to a stem cuneate
. They are pellucid-punctate along crenulate margins and are pubescent on and between veins.
Flowers appear as umbrella-like clusters from 2–12 in small terminal to axillary umbellate clusters. They are imperfect with pedicel
s 2–4 m long; there are 4–5 petals, elliptic to ovate-oblong 1.6–1.9 mm long and have green with reddish hairs near the tips; stamens 5; ovary with 2–5 carpels.
Fruit a follicle, with 2 seeds per carpel.
or other igneous rock, at elevations of 1350–1750 m (4,429.1–5,741.5 ).
The understory
is primarily native bunchgrasses with a mix of other cacti and herbaceous species. In shaded dense areas, the ground is sparsely inhabited with vegetation but covered with dense leaf litter.
and turns yellow in mid-October.
.
Rutaceae
Rutaceae, commonly known as the rue or citrus family, is a family of flowering plants, usually placed in the order Sapindales.Species of the family generally have flowers that divide into four or five parts, usually with strong scents...
. It is native to the mountains of Trans-Pecos
Trans-Pecos
The term Trans-Pecos, as originally defined in 1887 by the Texas geologist Robert T. Hill, refers to the portion of Texas that lies west of the Pecos River. The term is considered synonymous with "Far West Texas", a subdivision of West Texas...
Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
in Brewster
Brewster County, Texas
Brewster County is a county located in western part of the US state of Texas, along the border with Mexico. It is one of the nine counties that comprise the Trans-Pecos region of West Texas. As of the 2000 census, the population is 8,866. In 2009, the population was estimated to be 9,481. Its...
and Jeff Davis
Jeff Davis County, Texas
Jeff Davis County is a county in the U.S. state of Texas. It is named for Jefferson Davis, the president of the Confederate States of America. It is one of the nine counties that comprise the Trans-Pecos region of West Texas. In 2000, its population was 2,207, and 2,258 by 2009...
counties.
Alternative names
Zanthoxylum parvum is also known as Skinners' tickletongue and small prickly-ash.Description
Zanthoxylum parvum is a rhizomatous and deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
plant. It is a dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
shrub and can grow up to 2 m tall. Stems have erect prickles, sometimes curved, which occur either solitary or paired; they range from 4-13mm long. Zanthoxylem parvum are imparapinnate with alternate leaves and average about 7–13 leaflets. The rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
and petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
are not winged.
Leaflets are opposite, usually oval shaped with a tapering point or sometimes ovate or lanceolate; the leaflets range from 6–16(−35) mm long and 11–18 mm wide with an obtuse apex and a triangular attaching to a stem cuneate
Cuneate
Cuneate means "wedge-shaped," it can apply to:*cuneate leaf, a leaf shape*the cuneate nucleus, a part of the brainstem*the cuneate fasciculus, a tract from the spinal cord into the brainstem...
. They are pellucid-punctate along crenulate margins and are pubescent on and between veins.
Flowers appear as umbrella-like clusters from 2–12 in small terminal to axillary umbellate clusters. They are imperfect with pedicel
Pedicel (botany)
A pedicel is a stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower....
s 2–4 m long; there are 4–5 petals, elliptic to ovate-oblong 1.6–1.9 mm long and have green with reddish hairs near the tips; stamens 5; ovary with 2–5 carpels.
Fruit a follicle, with 2 seeds per carpel.
Habitat
Underlies of maple-oak woodlands or dense growth of small trees like evergreen oak on rocky, often shallow, well-drained, tuffTuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
or other igneous rock, at elevations of 1350–1750 m (4,429.1–5,741.5 ).
The understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
is primarily native bunchgrasses with a mix of other cacti and herbaceous species. In shaded dense areas, the ground is sparsely inhabited with vegetation but covered with dense leaf litter.
Phenology
Zanthoxylum parvum flowers in late March till early April, before its leaves have expanded fully. Although foliage is present throughout most of the year it eventually becomes deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
and turns yellow in mid-October.
Comments
Zanthoxylum parvum is a rare and poorly understood plant from a few populations in the Davis MountainsDavis Mountains
The Davis Mountains are a range of mountains in West Texas, located near Fort Davis, after which they are named. They are a popular site for camping and hiking and the region includes Fort Davis National Historic Site and Davis Mountains State Park...
.