More vining invasives

Following up on my 8/26 posting on vining invasives, one more from visits to the Gamble Garden in Palo Alto: the trumpet vine, Campsis radicans, which leads us to other vines in its plant family, the Bignoniaceae (among them the crossvine, Bignonia capreolata), and to some non-vining plants. And then another vining invasive, the dreadful Oriental bittersweet, Celastrus orbiculatus.

The invasives tend to be multiple-threat plants: they smother the competition, spread by creeping, and/or distribute their seeds widely, especially when their fruits are eaten by birds or other creatures.

A few pictures: Campsis radicans (#1), Bignonia capreolata ‘Tangerine Beauty’ (#2), and Celastrus orbiculatus (#3):




Background. My earlier posting looked especially at porcelainberry, grape vines, and common ivy, all of which have their uses (as ornamental plants or food) but can be seriously threatening. And it provided links to earlier postings on vining invasives, some of them quite fearsome.

Now to Campsis radicans (Latin radicans ‘rooting’), a gorgeous flowering vine that sprawls over fencing at the Gamble Garden (and, like many plants in its family, has tubular flowers that attract hummingbirds). From Wikipedia:

Campsis radicans (trumpet vine or trumpet creeper, also known in North America as cow itch vine or hummingbird vine), is a species of flowering plant of the family Bignoniaceae, native to the eastern United States and naturalized in parts of the western United States as well as in Ontario, parts of Europe, and scattered locations in Latin America. Growing to 10 m (33 ft), it is a vigorous, deciduous woody vine, notable for its showy trumpet-shaped flowers. It inhabits woodlands and riverbanks, and is also a popular garden subject.

… The flamboyant flowering of Campsis radicans made it obvious to even the least botanically-minded of the first English colonists in Virginia. Consequently the plant quickly made its way to England early in the 17th century.

… The vigor of the trumpet vine should not be underestimated. In warm weather, it puts out huge numbers of tendrils that grab onto every available surface, and eventually expand into heavy woody stems several centimeters in diameter. It grows well on arbors, fences, telephone poles, and trees, although it may dismember them in the process. Ruthless pruning is recommended. Outside of its native range this species has the potential to be highly invasive, even as far north as New England. The trumpet vine thrives in many places in southern Canada as well.

Native, but invasive.

The family is large and includes many tropical and subtropical plants:

The Bignoniaceae, the bignonias [or catalpa family], are a family of flowering plants in the order Lamiales. It is not known to which of the other families in the order it is most closely related.

Nearly all of the Bignoniaceae are woody plants, but a few are subwoody, either as vines or subshrubs. A few more are herbaceous plants of high-elevation montane habitats, in three exclusively herbaceous genera: Tourrettia, Argylia, and Incarvillea. The family includes many lianas, climbing by tendrils, by twining, or rarely, by aerial roots. The largest tribe in the family, called Bignonieae, consists mostly of lianas and is noted for its unique wood anatomy.

… Bignoniaceae are most noted for ornamentals, such as Jacaranda, Tabebuia and Spathodea, grown for their conspicuous, tubular flowers. A great many species are known in cultivation.

… Misidentification of plants, even by botanists, continues to be a big problem for ethnobotany, and it is especially severe for Bignoniaceae. Voucher specimens are often sterile and fragmentary, making them nearly impossible to identify. (Wikipedia link)

On the type genus:

Bignonia is a genus of flowering plants in the catalpa family, Bignoniaceae. Its genus and family were named after Jean-Paul Bignon by his protégé Joseph Pitton de Tournefort in 1694. (Wikipedia link)

And one of its American species:

Bignonia capreolata is a vine commonly referred to as crossvine. The common name refers to the cross-shaped pattern revealed when the stem is cut; this pattern results from four radial wedges of phloem embedded within the stem’s xylem. It is native to the central and southern United States. The vine climbs without twining but does produce tendrils. It produces long tubular flowers which are red and yellow and frequently have a mocha fragrance. The leaves are dark green to almost purple and produced as opposite pairs with terminal tendrils. The vine often climbs very high, with leaves only remaining on the uppermost portion of the plant. Crossvine can spread aggressively through stolons and become invasive unless properly managed. (Wikipedia link)

Again with the invasiveness theme.

The Bignoniaceae have come up on this blog at least once before, in a posting “From South America” of 6/26/12, about two plants that bloom gorgeously in the late spring: the jacaranda tree (in the Bignoniaceae) and the garden ornamental alstroemeria (in the small family Alstroemeriaceae, with about 200 species in 3 or 4 genera). More information, and photos, in my 2012 posting, plus an alstroemeria photo in a 7/23/15 posting. The alstroemerias are still blooming at GG.

Back to the vines, with Celastrus, which Robert Coren reminded me about in a comment on “Vining invasives”. From Wikipedia:

Celastrus orbiculatus is a woody vine of the Celastraceae family. It is commonly called Oriental bittersweet. Other common names include Chinese bittersweet, Asian bittersweet, Round-leaved bittersweet, and Asiatic bittersweet. Celastrus orbiculatus was introduced into North America in 1879, and is considered to be an invasive species in eastern North America. It closely resembles the native North American species, Celastrus scandens, with which it will readily hybridize.

The defining characteristic of the plant is its vines: they are thin, spindly, and have silver to reddish brown bark. They are generally between 1 and 4 cm (0.4 and 1.6 in) in diameter. When Celastrus orbiculatus grows by itself, it forms thickets; when it is near a tree or shrub, the vines twist themselves around the trunk. The encircling vines have been known to strangle the host tree to death, which is also true of the American species, C. scandens. The leaves are round and glossy, 2–12 cm (0.8–4.7 in) long, have toothed margins and grow in alternate patterns along the vines. Small green flowers produce distinctive red seeds [see #3 above] which are encased in yellow pods that break open during autumn. All parts of the plant are poisonous.

... Oriental bittersweet is a strong competitor in its environment, and its dispersal has endangered the survival of several other species. One attribute that contributes to the success of this species is having attractively colored fruit. As a result, it is eaten by mammals and birds, which excrete the seeds to different locations.

Summary. Three invasive vines, two of them American natives, the third with a somewhat invasive American cousin so closely related to it that they can hybridize.

And three plant families (one huge, two small): Bignoniaceae, Celastraceae, and the non-vining Alstroemeriaceae. Running total: 41.

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