Dangerous Plants – Miller Springs Nature Center

In the nature center there are many hundreds of different species of plants, a few of which can be dangerous to people. Presented here are some of those that you will find most commonly alongside the many paths in the Nature Center. In an effort to keep the nature center as pristine as possible we try to interfere as little as possible with the plants and animals. This list is not intended to be complete but to give some representative examples of the most commonly found species.

There are 3 basic types of plants that can be dangerous to people. First, some plants have oils which are strong allergens. Others have thorns, needles, spikes or hooks that are painful when touched. Finally there are those which are poisonous when eaten. The poisonous parts of plants can include the berries, leaves, stems and roots! The park volunteers which maintain the nature center have removed the majority of these plants that grow in the paths so that the average person does not need to worry about them. If you go off of the paths then it is recommended that you learn to recognize these plants.

If you are not certain about a plant you should assume it is poisonous. You will usually be correct!

Plant Type Latin Name Danger
American Mistletoe Tree Parasite Phoradendron tomentosum Berries fatal, all parts poisonous
Betony Noseburn Shrub Tragia betonicifolia Stinging Hairs, Poisonous
Bristly Greenbriar Vine Smilax tamnoides Extremely Thorny!
Catbriar Vine Smilax bona-nox Large Thorns
Chinaberry Tree Melia azedarach Poisonous berries, leaves, flowers, bark
Common Prickly-Pear Shrub Opuntia macrorhiza Foot danger – large, small thorns
Honey Mesquite Tree Prosopis glandulosa Very large thorns
Poison Ivy Vine Toxicodendron radicans All parts – strong delayed reaction
Silverleaf Nightshade Shrub Solanum elaeagnifolium All parts – unripe fruits fatal
Southern Dewberry Vine Rubus trivialis Thorns
Twistleaf Yucca Shrub Yucca rupicola Sharp leaf tips

Work In Progress

American Mistletoe – Phoradendron tomentosum
This holiday plant loves to hang around in trees! It is actually a parasite and sends its roots into the branches drawing nutrients and water from the tree. It has interesting looking white berries and succulent foliage but one should not eat either as it can be fatal. The berries are particularly toxic and can cause heart failure. It is often known as the “Christmas Mistletoe” due to its popular use during the Christmas season.
Phoradendron_tomentosum_02_closeup_half Phoradendron_tomentosum_02c_foliage_half
Betony Noseburn – Tragia bentonicifolia
This plant can easily sneak up on you! It is a low growing plant and is often found alongside our paths in both sunny and shady areas. It is covered with tiny stinging hairs that you will not want to touch. You will know if you have brushed up against this plant because of an unpleasant and sharp stinging pain. Fortunately the discomfort is not too strong and will last only 15 to 20 minutes!
Betony Noseburn - Tragia betonicifolia plant Betony Noseburn - Tragia betonicifolia stinging hairs
Bristly Greenbriar – Smilax tamnoides
Amazingly enough, the greenbriars are a member of the Lily order! The catbriar and greenbriar are the only 2 vines in the park with both tendrils and thorns. The Bristly Greenbriar is easily distinguished from the greenbriar because its stems are covered with large numbers of both large and small thorns. The thorns on this vine are vicious and you should not try to pull the plant out with your hand. It is also very efficient at grabbing pants, shirts as well as bare skin if you brush up against it. It is usually seen as single vines and is not thicket forming.
Bristly Greenbriar - Smilax tamnoides Bristly Greenbriar - Smilax tamnoides
Catbriar – Smilax bona-nox
Catbriars are very common in the park. It is very easy to distinguish the Catbriar from the Bristly Greenbriar by its very tough, green and isolated triangular thorns growing on a rather smooth and sometimes square stem. It also has distinctive mottled leaves often found with strong indentations. It is often found growing in dense thickets. These vines can be very large and tough to break so it is best to go around them whenever possible.
Catbriar - Smilax bona-nox Common Greenbriar - Smilax rotundifolia thorns
Chinaberry – Melia azederach
This beautiful tree is very common in the nature center. It is very easy to distinguish from other plants by it dark green leaves, marble-sized berries, purple flowers and fairly smooth dark trunk covered with white horizontal dashes. Unfortunatey the berries are very poisonous to nearly all animals and especially humans. The leaves and bark are also poisonous and so it is very insect unfriendly! The tree is weak because it usually has a center that is dead and so often is blown over by the wind. The leaves and berries change the soil so that other plants (even other chinaberries) have a difficult time growing there.
Melia_Azederach_04_tree_TN Melia_Azederach_04b_foliage_TN
Common Prickly-Pear – Opuntia macrorhiza
The common prickly pear has one of the most beautiful flowers of all of the cacti species found in the nature center. It is also one of the most dangerous plants around if you get off of the trail. Small plants effectively hide in the undergrowth and can easily puncture the sides of most shoes. Do not try to touch this plant because the smaller spines easily detach and will stay in your hand. Sitting or falling on one is also no fun at all (from personal experience) and so it is definitely not recommended. The pads and fruit on this cactus are edible but one has to remove all of the spines first. The Indians did this by burning them off using fire. The petals of the flowers may be used in a salad.
Common Prickly Pear - Opuntia macrorhiza Common Prickly Pear
Honey Mesquite – Prosopis glandulosa
Honey Mesquite can be dangerous as a small vine-like bush if you are walking along the trails. It is a very good ankle biter! As a tree it is very beautiful but one also has to watch out for the huge thorns on the limbs. The thorns are woody and very strong. They can cause major damage to anyone who accidentally runs into one of these! For nature lovers the mesquite, because of its thinner foliage is very friendly to plants growing underneath it and also to the many types of lichens growing harmlessly on its bark. The tree is a hardwood and is especially useful when smoking meats on the barbeque.
Honey Mesquite Tree - Prosopsis glandulosa Honey Mesquite Thorns - Prosopsis glandulosa
Poison Ivy – Toxicodendron radicans
Poison Ivy is probably the most feared plant in the park. It has several forms and can appear as a woody plant or vine. Fortunately it is rather easy to recognize. The first thing to look for are the 3 leaves grouped at the tip of a vine. Second, the stem is usually red. Next, if you examine the leaves you will usually see a few that have side lobes. Finally, the leaves down the stem are paired, in other words side by side. All parts of the poison ivy plant should be avoided. Grape vines climbing up the side of a tree are often mistaken for poison ivy. Again, the poison ivy vines are very easy to pick out as they are covered with innumerable tiny hairlike rootlets as seen in the photo below. It is most often found in shady moist areas. It is interesting that this plant only affects people and is very beneficial to wildlife and insects!
Poison Ivy leaves and flowers Poison Ivy - Toxicodendron radicans lwaves and flowers
Silver-Leaf Nightshade – Solanum elaeagnifolium
The silver-leaf nightshade is one of the most common plants found along the paths in the nature center. It is easily recognizable by its purple flowers with prominent yellow centers and small pale-yellow fruit. It is in the same family as tomatoes and potatoes but do not eat the fruit as it is quite poisonous! In fact the entire plant is poisonous. Do not try to pull this plant out with your bare hands as the plant is covered with tiny needle-like nettles and it can be quite painful.
Silver-leaf Nightshade - Solanum Elaeagnifolium Silver-leaf Nightshade - Solanum Elaeagnifolium fruit
Southern Dewberry – Rubus trivialis
These plants are very common in many parts of the park. They have wonderful berries in the spring and small white flowers. They also have numerous tiny sharp thorns and strong roots so it is not good to try to pull on one of these vines with ones bare hands. The are not very dangerous and mostly are difficult to walk through as they often form dense low tangles of plants.
Southern Dewberry - Rubus trivialis Southern Dewberry - Rubus trivialis thorns
Twistleaf Yucca – Yucca rupicola
This wonderful spiky plant occurs throughout the park and is always easy to spot. This plant gets its name from the long pointed leaves that tend to twist as the plant gets older. It loves to grow in open rocky areas and is very heat tolerant although it is also often found nesting under trees in the forest on the slopes of the canyons. It has wonderful white flowers on a tall spike in the spring and the deer love to eat the buds! The leaves can grow to 2 feet long and are tipped with a very sharp spike. Stepping over this plant is not adviseable as the leaf tips are sharp and quite strong and so can inflict serious damage to your ankles or legs.
Twistleaf Yucca - Yucca rupicola flower Twistleaf Yucca - Yucca rupicola basal leaves

Special Request

The Miller Springs Alliance is working hard to improve and maintain the trails and animal habitat in the Nature Center. This includes the grooming of trails, removal of fallen trees, removal of more than a thousand invasive trees and thousands of invasive plants in the past year alone. It also includes the construction of animal habitats.

All of this work is done by volunteers and we need your donations and help! Please sign up for “Friends of the Park News” (right column) to be notified of upcoming volunteer events. All purchases of tools and other materials critical to improving and maintaining the park are made using donations by the general public and the occasional grant by local groups. Please visit our donations page to help us support the nature center!