Are crepe myrtles poisonous to dogs?
Yes, they are very poisonous to dogs.
From the article linked:
Though it appears that the toxin is relatively safe for dogs, they still don't like it, just like cats don't like eating lettuce. There are no studies on the effects of leaf extracts or crepe myrtles in humans so the information in this article is not necessarily applicable to other species.
The toxicity of crepe myrtles is one of the primary reasons the plant is not commonly used in modern gardens. The chemical makeup of crepe myrtles is such that no amount of ingestion can be tolerated, leading to death usually within one or two hours.
From Wikipedia - Crepe myrtles
Myrtles (including crepe myrtles) are toxic to humans and animals, and
include poison sumac, poison ivy and poison oak, and they may cause
severe dermatitis. Crepe myrtles are not considered a dangerous plant by
the International Poison Control Center or the American Association of
Poison Control Centers. However, some pets dislike crepe myrtles.
I don't think the plants taste good anyway, so why eat them?
Crepe myrtle is native to the Southeastern United States and is
widely planted as a hedge or a specimen plant. It prefers partial to
full shade and tolerates drought. Crepe myrtle is extremely
shade-tolerant and grows well in most situations, but like most
species of this genus it does poorly if allowed to compete for light.
Dangers and warnings:
Poison ivy and poison oak are not the only poisonous members of the
genus Myrtus, as also called ivy-leaved myrtle. Other species include
crepe myrtle (Myrtus communis), also called ivy myrtle and common
ivy, which is less well known and often confused with poison ivy. In
fact, some old sources warn that poisoning by crepe myrtle (Myrtus
communis) and poison ivy is far more likely than by poison oak. Some
species of poison ivy are considered poisonous to livestock, including
cows and horses.
The toxicity of crepe myrtle (Myrtus communis) is about 20 times
greater than that of poison ivy, although its leaves and buds are not
the easiest ones to mistake. Poison ivy is more poisonous than the
crepe myrtle because it has a higher concentration of irritant urushiol
than crepe myrtle does. Poison ivy has also been known to cause
problems in people without the dermatitis-producing property of its
oil, and can be an irritation in the eyes.
Source: USDA Plants Database
Why do I say it is poisonous?
Myrtus communis contains L-3-methoxytyramine.
L-3-methoxytyramine (3-methoxytyramine, 3-methoxy-β-hydroxyleucine)
is a beta-phenylethylamine alkaloid and putative neurotransmitter in
the human brain. It is a by-product of the degradation of norepinephrine
by monoamine oxidase A. Methoxytyramine is a naturally occurring
analog of the neurotransmitter dopamine. It is considered to be an
agonist of the sigma 1 receptor and can cause ataxia. The sigma 1
receptor, discovered by the National Institutes of Health (NIH), is a
transmembrane protein that is a part of the endoplasmic reticulum
membrane. It is named for the fact that it is closely associated with
sigma (σ) sites.
Why does the wiki source state that myrtle is a hallucinogen?
There's a lot of info, I'm not sure where to start.
The short answer: It is not hallucinogenic.
What is a hallucinogen?
In psychology and neuroscience, hallucinogens are chemicals or plants
that affect the perception, judgment, or emotions of a user.
I'm not sure if this applies to you or not, but this is probably a good place to start for you.
If you want to continue, I'd say the two articles in Wikipedia are what you're looking for, as they cite quite a bit of good resources.
The first one I linked is a little shorter. I think it's best to look at the long one first. If you're still unsure, go to the first link and read the short one.
This plant is indeed one of the sources of the psychoactive drug Myrtus communis (Myrtle) that is used to induce some of the psychedelic experiences in people, in particular the myrtle cup, or the myrtle tea which contains the volatile alkaloid myrtol.
Wikipedia also states that
A number of myrtle species, including M. communis and M.
coronaria, produce myrtle ketone, which can induce a state similar to
that induced by ayahuasca.
The myrtle has many compounds and alkaloids such as:
- Acetonyl myrtanol
- Vincristine sulf