Chamaesyce hirta is a taprooted warm season annual with erect, hairy branched stems. Leaves are opposite, with differentiating base as well as being hairy with teeth on the margins. Flowering mid-through late-summer, Garden Spurge can be found in South Carolina, south throughout Florida and west to Alabama.
Facelis retusa is a winter annual with freely branched stems at teh base. Facelis leaves are narrow in shape with a dull green upper surface and a lower surface covered with white turfs of long hairs. Facelis can be found in Tennessee and North Carolina, and south into north Florida and west to Texas and Oklahoma.
Florida has a variety of weeds that are damaging to your healthy lawn.
Paspalum dilatatum also known as Caterpillar grass, Dallisgrass is a warm-season clumpy perennial with tall, pointed, membranous ligules. Leaves are rolled in the bud, fat and wide, with fine hairs on the lower section of the leaf. Dallisgrass can be found throughout the Southern United States from the mid-Atlantic west to Tennessee.
Stellaria media is a mat-forming winter annual or short-lived perennial in temperate regions and is identified by alternating, shiny leaves – egg or oval, to broadly elliptic, in shape. Upper leaves are without petiole; while the lower leaves have sparsely, hairy long petiole. Found throughout North America with the exception of the Rocky Mountains.
Richardia scabra L. is a summer annual with branched, densely hairy stems from a taproot. The alternating leaves are oval-shaped and slightly rough with hairy margins and can be identified by its white, tubular, clustered flowers at the end of its branches. Florida Pusley can be found in the Southeast, Northeast and Midwestern Unites States.
Cerastium vulgatum is a winter perennial with alternating leaves that are oblong and covered with hair. Prostrate overall, Mouse-ear Chickweed will have several upright stems. The weed can further be identified by the white flowers containing five pedals that are notched at the ends. Mouse-ear Chickweed can be found throughout the United States.
C ertainly one of the most painful hitchhiking plants in the southwestern United States is jumping cholla (Opuntia bigelovii). Although it only received 5 SRDUs for removal from interwoven socks, the spines are exceedingly difficult to pull out of rubber soles and elastic human skin. Like other kinds of cholla cactus, the cylindrical stem segments are densely covered with slender, barbed spines. In fact, this species is sometimes called "teddy-bear cholla" because of its dense covering of spines. What makes this cholla so unique is that the stem segments or joints break off with the slightest touch and become firmly attached to various body extremities. Unlike the unrelated but truly amazing Mexican jumping beans and California jumping galls, this cholla doesn’t really jump. If you barely touch or brush against the spines and then suddenly jerk away, the fuzzy stem fragment will be instantaneously upon you. Trying to pull out the barbed spines is not only frustrating and excruciating, but usually results in the joint or fragment becoming attached to another part of your anatomy. On a field trip to the Anza-Borrego Desert of San Diego County, several students attempted to remove a segment from a lady’s shoe, only to have it transferred to the shoes of each chivalrous male. It finally ended up on the hand of a screaming (bleeding) student who promptly flipped it full force into Mr. Wolffia’s groin region. From that day forward the Wayne’s Word staff always carries a pair of needle-nose pliers when walking through jumping cholla country.
Conclusions About Hitchhiking Plants
T wo more hitchhikers with Wayne’s Word ratings of 10 SRDUs are krameria (Krameria grayi) and stick-tight (Desmodium cuspidatum). Krameria is a small, purple-flowered shrub of the Colorado Desert region of southeastern California. The amazing hitchhiker fruits are like miniature versions of the legendary Uncarina of Madagascar. The fruit is covered with radiating spines, each spine tipped with several minute hooks or barbs resembling a tiny harpoon. In a related species (K. parvifolia) the barbs are scattered along the upper portion of each spine. Although the flowers resemble a lovely orchid, krameria actually belongs to its own family, the Krameriaceae. Kramerias are also quite fascinating because they are partially parasitic on the roots of nearby shrubs.
O ne of the "super hitchhikers" of southern California, Baja California Norte, and the offshore California islands is a low-growing annual called "stick-tight" (Harpagonella palmeri). In the official Wayne”s Word Top 17 Hitchhikers, this species receives 10 SRDUs, although it is almost as difficult to remove from your socks as the previous species. This hitchhiking plant is occasionally encountered on dry slopes and mesas of coastal San Diego County. The fruit of this rare wildflower is composed of two small nutlets enclosed in a burlike calyx. The persistent calyx is armed with 5-9 spines, each with minute, hooked barbs. The generic name Harpagonella is derived from the Latin word "harpago" or grappling hook. Like a grappling hook, the burs become deeply embedded in fibrous material and are practically impossible to pull out.
O ne of the most interesting cases of hitchhiking involves seabirds and a tropical pisonia trees of the four o’clock family (Nyctaginaceae), including Pisonia umbellifera and P. grandis . On some atolls of the South Pacific, pisonia is the only dominant tree on otherwise barren islets. Marine birds use the large, edible leaves to construct nests in the trees. Pisonia trees produce tiny white flowers in terminal, many-flowered clusters. Individual apetalous flowers have a tubular, petaloid calyx that resembles a sympetalous corolla. The lower portion of the calyx tightly enwraps the ovary and is persistent around the fruit as an anthocarp. The calyx base plus the enclosed seed-bearing fruit is the unit of dispersal. In some members of the Nyctaginaceae, the persistent calyx base bears sticky glandular projections that aid in dispersal by adhering to the bodies of animals. This is especially true in pisonia trees in which the numerous glutinous anthocarps stick to the feathers of seabirds. This is an effective method of dispersal to distant atolls and islands of the South Pacific region. Sometimes a hapless seabird is completely covered by clusters of the sticky anthocarps, to the point where flight is difficult or impossible. Unable to remove the water-resistant, glue-like anthocarps from its feathers, the seabird drowns in the surf and is consumed by ravenous beach crabs.
P uncture vine belongs to the caltrop family (Zygophyllaceae), so named because of the shape of the wicked fruits. At matury, the fruit dries and breaks apart into five seed-bearing sections called carpels. Each section is armed with several sharp spines that readily penetrate bicycle tires or your shoes.
Note: Ranking & SRDUs are purely hypothetical without any quantitative data to support them.