A Powerpoint presention by Linda Curtis, botanist
Presented to Citrus Chapter of Florida Native Plant Society and Friends of the Lower Suwannee River, Cedar Key, Florida
Bandaid Botany is about local spiny and thorny plants, some native and some horticultural. The Florida State Horticultural Society lists over 30 spiny and thorny species commonly planted, and even more plants growing in the wild. This presentation includes 23 spiny or thorny species plus many images.
Also included are plants that you could trip on, such as vines and also slip on, such as ground algae. Last, you’ll see a few insects that have poisonous spines or bites.
So why do we grow plants with thorns that stab, pierce, puncture, or scratch us? Why suffer a pruner’s nightmare?
The answer is that we see more advantage than risk.
Beautiful flowers or long flowering period Statuesque form-pleasing plant architecture
Barrier or hedge-discourages foot traffic Host plants for caterpillars of our favorite butterflies Fruits-crabapples, plums, kumquat, dewberries
Title page shows native plant Cnidoscolus stimulosus, or tread softly” also known as finger rot. Probably the number one reason the Native Americans in this area wore moccasins; it was too risky to walk barefoot in the pine-oak forests.
Individual images also available on Florida Plant Atlas. florida.plantatlas.usf.edu/
1. Apple tree flowers help identify our only native apple tree for this Central Florida area. The southern crabapple, Malus angustifolia, is grown as an ornamental for its pretty flowers. The fruits are small, barely edible crabapples.
2. Thorns of Southern crabapple are pointed twigs, and by definition, thorns have buds or leaves. They appear similar to hawthorns but there are no native hawthorns in Central Florida and those hard fruits are not edible.
3. Our southern crabapple has small narrow leaves compared to domestic apple trees. The leaves also have irregular marginal teeth that help distinguish it from the next species, a wild plum with finely serrate leaf margins.
4. Our native plum, Prunus umbellata also has thorns with buds and leaves that grow as sharp twigs. Flatwoods plum,
also known as scrub plum, has edible fruits either raw or when de- stoned, the dried plums are prunes.
5. Both thorny trees are in the Rosaceae family and have flowers with 5 petals, but plum tree fruits have a single stone with a seed inside, while apple have 5 carpels with many small, toxic seeds.
6. Spines are different from thorns. Acorns have spines at the tip. Turkey oak acorns have fairly blunt tip compared to live oak acorns. The caps actually pressure squeeze the acorn out of its cap and that aids in their dispersal.
7. Turkey Oak is Quercus laevis. Young leaves are red and the lobes end in spine tips. Acorns are wildlife food.
8. Their leaf shape is 3 or 5 lobed. I used the leaves on my handout for my talk 3 years ago “A Sandhill Primer” about the drought tolerant plants in the pine-oak sand hills forest. The “dance of the turkey oak leaves” occurs each autumn as the leaves twirl around in the wind.
9. Sandhill live oak, Quercus geminata has a long spine- tipped acorn. The hole in the acorn reveals it had a borer insect. The healthy acorns have already fallen.
10. Acorn caps usually persist on the trees. If a fallen acorn has a cap, the tree aborted it early probably not good for animal food or planting. Acorn soup and ground acorn flour are still used today,
but the tannins must boiled out or soaked out.
11. The Agave family includes Agaves and Yuccas. This image from Kingsley Taylor’s Book is Yucca aloifolia, Spanish dagger. It grows in
wet places along the coasts, although some are planted by homes. The risk factor is high, since the sharp are spines over 1 inch long.
12 &13. Agaves and Yucca have spine tips, but Agaves have side teeth. Both genera have a panicle of flowers on a tall stalk, but Yucca flowers are different from the Agaves.
14. Agaves are planted because they are statuesque and stately, but they should have a wide mowing zone around them, since they are high risk to lawn mowers.
15. Beargrass is a common name for Yucca, but also for Eryngium in Apiaceae family, while Yucca are in Agavaceae. Flowers will tell, and Erygium yuccifolium a different native plant named rattlesnake master will grow button-like flowers in summer.
16. Adam’s needle, Yucca filimentosa, has upright sword-shaped leaves with needle-like tips. Its common name suggests the first needle.
17. The threads are plant fibers filaments along the edges. Adam’s needle’s sword-like leaves do not have teeth along the margins.
18. Adam’s Needle grows at Withlacoochee Gulf Preserve in Yankeetown, where ground water is only 3 feet below the soil surface, but also grows in the sand hills where the water table is 60 feet or more below the surface.
19. An anole lizard has a good hiding place on the Adam’s needle leaf. If bird swoops, the bird may get the point and possibly miss the anole.
20. Even anoles stay away from Cenchrus echinata, sandspur, grasses with spiny seed heads. This may be Florida’s number one nuisance plant.
21. A sandspur bur under a microscope has many smaller spines. They can attach to the underside of your shoe and be carried into the house and transferred into the carpet.
22. Sandspur is an annual and reseeds every year so short mowings often helps to kill off spikes before they mature. This plant appears to be all risk with no advantage, but it is does give roadside erosion control in doughty sand.
23. Opuntia humifusa, our native prickly pear cactus is a visible risk with its large spines. On the advantage side, they are interesting to see and the thick pads and fruits are edible. The pads, which are stems, are peeled and cut into strips for pickles, or cubes for chili con carne.
24. Cactaceae, the Cactus family, has some species with leaves, but not ours. Also, there is a spineless prickly pear near S. Am. that is used a sheep food, but ours are all spiny.
25. Cotton blotches on Cactus are evidence of scale insects that make these cottony patches to cover themselves.
26. The Cochineal scale insect produces carmine dye, and is used as the red dye in foods and cosmetics. Today, red dye is made synthetically as well.
27. If poked with a stick, sure enough, a red color oozes from the cottony mass.This dye made the red in British uniforms, the “Red Coats.” Imagine collecting enough of these to dye one uniform.
28, 29. Not all cactus appearing plants are in the Cactaceae family. Some spiny cactus are in Euphorbiaceae. Cactaceae differ by also having small circles with tiny spines.
30. Poncirus trifoliata, mock orange, has spines as thick as thorns, and are in the axils of leaves. This plant has small poisonous fruits, causes rashes, blindness, and is invasive!
31. Mock orange is the rootstock of most orange and grapefruit trees. If a frost kills the grafted tree, the base spouts, and the new stems with long spines have trifoliate leaves while citrus trees have simple leaves.
32. Kumquat, an Oriental relative of citrus trees has the advantage of edible fruits, but has sharp spines.
33. Apparently, the edible raw fruits of kumquat are worth the risk of its thorns. But what about mock orange? Its fruits are gooey with lots of seeds and taste terrible. The advantage is its leaves are caterpillar food.
34. Mock orange leaves are the larval food for swallowtail caterpillars. The giant swallowtail butterfly lays an egg here and there on the leaves.
35. Another value of the thorny kumquat is its photographic value. Many or our northern visitors like to pose with it for a photo.
36. Wild thorny plants like the blackberries and dewberries have edible fruits as the compensating factor. Both in Rosaceae, the Rose family.
37. Dewberry, Rubus trivialis, is a low shrub, grows in patches, and has hooked barbs, a problem in pastures for dairy cattle and beef cattle. We who walk on two legs do not suffer as much as the 4-legged animals.
38. However, if you Google “Rubus trivialis plant patent” you will find a new natural clone, a sweet gold fruited dewberry, that grew in Texas. Not true to seed, the plants are air-layered and sold as nursery stock.
39. Ow. The high risk of this plant makes it a candidate for teaching about safety on field trips for our public schools. Cnidoscolus stimulosis, is aptly named “tread softly,” or “finger rot”.
40. Prounounced “nid-ah-sco-lus,” finger rot is a cute, low growing plant that blooms all year round in woodlands.
41. Even the leaves have thin inconspicuous spines. Remove these from sides of walking trails in woodlands where children are on fieldtrips, and observe the “Stay on the trail” signs.
42. Pretty white flowers are not advantage enough for that risk. Yet, association with a mythical person, may be an advantage, as the next plant associated with Hercules.
43. Hercule’s club is the common name of Zanthoxylum clava-herculis, also in the Citrus family Rutaceae. Four young trees grow in the Dixie Shores birding trail, off Ft. Island Trail, Citrus Co. After entering, follow the right trail.
44. In a few years, the trunks could be cut to make impressive spiny clubs, known as “persuaders.” The leaves have pairs of purple curved spines.
45. The large caterpillar chew marks tells us it is an important plant because the caterpillars are bird food, so it has ecological value, as well as value as a novelty tree.
46. Serenoa repens, sawtooth palmetto, has ecological value because it provides food and shelter for wildlife. The Florida panther uses these thickets for resting.
47. The sharp serrate teeth along its petioles helps distinguish it from similar Sabal minor, dwarf palmetto.
48. Sawtooth palmetto has small trunks that look like small palms when lower leaves are pruned off, but be careful and wear gloves when pruning.
49. Be careful with disposal of the pruned leaves, the serrate teeth on the petioles are even tougher when dry.
50. Sabal minor does not have teeth on its leaf petioles, and it has an underground trunk so the leaves emerge from the ground, different from Serenoa repens which has a short trunk.
51. A popular planted cycad, the Sago palm, has spine-like young leaves that gradually enlarge into larger leaves.
52. Small pretty white flowers grow along roadsides and survive some mowing. They are called white marigold, Bidens alba, and “alba” means white in Latin. They are also called beggarticks and Spanish needles.
53. As a butterfly and skipper host plant for caterpillars, it is ecologically beneficial. It is also makes a medicinal tea, and the flowers are visited by honey bees. So, those are the benefits, what is the risk? Irritation.
54. The irritating needles are the two-forked or three-forked achenes. An achene is a dry fruit seed of the Asteraceae the Aster family. They survive the laundry and persist in socks and other clothing and jab you later.
55. If flowers of Spanish needles are removed before they go to seed, they can be controlled, but seldom eradicated because they are dispersed as hitch-hikers.
56. The backward pointed barbs of Spanish needles makes them difficult to remove from clothing.
57. Some thorns are not real thorns, and sweetgum trees often have scale insects that mimic thorns.
58. Liquidambar styraciflua, sweetgum, has spiny fruits, sharp enough to make a barefoot person shout if stepped or sat on. An advantage is the leaves pretty autumn color.
59. Vines are trippers when they grow on the ground until they reach a shrub or tree, then grow upwards. A vine like Smilax bona-nox will trip you and then claw you and stab spines in you on your way down. (Audience shutters).
60. Smilax auriculata, catbrier, is common in the sand hills and it does not have spines on its leaves, but its curved stem spines make long scratches resembling cat scratches.
61. Two vines here, the invasive air potato, a wild African yam Dioscorea bulbifera, is twining around the vine of catbrier. Both have edible tubers and are survival foods.
62. Catbrier (Smilax sp.) has large underground tubers that are edible when properly cooked. Introduced and now wild, air potato has aerial tubers on its vines.
63. Another tripper, Woodbine, Parthenocissus quinquefolia, offers some of our best autumn red colors. Beware, so does poison ivy, Toxicodendron radicans. while woodbine has 5 leaflets, poison ivy has 3 leaflets.
64. Woodbine may grow on the ground, often with sand spur. What is the risk of not watching where you step?
65. Tripper morning glory, Ipomoea purpurea has flowers in a range of colors white to rose to purple. There are 25 species of morning glories in Florida.
66. Tripper Ipomoea pes-caprae, railroad vine, grows along the coasts and stabilizes the sand dunes until other plants seed in.
67. Tripper Vitis aestivalis, summer grape is very common and if planted, could be trained to a trellis and pruned to produce grapes.
68. Slippery Nostoc commune, ground algae, oozes as a living gelatinous thallus, less than one inch tall, in masses. A Cyanobacteria, a blue-green algae, its ancestors were alive on the planet before plants evolved.
69-81. Stinging insects: dangerous saddleback caterpillar so cute in appearance. The Io moth caterpillar is covered in stinging hairs. Biting insects. The wheel bug should not be picked up. Tiny chigger mites in Spanish moss. Microwave Spanish moss 5-10 seconds before allowing in the house. Last, a thorn-mimicking thornbug, more dangerous dead than alive because it dries hard. Going barefoot has many risks. You never know when the risk/advantage balance will tip.
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