nerd's page

The nerd's page provides detailed information regarding the plants listed on the dangerous plants page, including sources. 

Red type indicates a clickable link.

About sources: 
Many plants have a reputation for being toxic or poisonous yet no credible sources were found while compiling these pages to confirm the reputation. Those plants aren't included on this blog. All listings on the garden at mom's house include at least one credible source. 
Is Wikipedia a trustworthy source of information? While many people distrust Wikipedia, in reality it is often an excellent 'first stop' when researching. There are many well edited Wiki pages, especially for non-controversial fact-based topics. A good Wiki page should list sources. As a general rule, when researching, never rely on a single source, unless you know it to be definitive (university, government, peer review journals etc). Even then, it is best to find corroborating sources.

outdoor

buttercup
(kingcounty.gov) Toxin: protoanemonin Parts: all parts of the fresh plant. The toxin breaks down with drying, so dried buttercup is safe. Indications: Burning mouth and throat sensation, mouth ulcers, abdominal pain, nausea, vomiting, diarrhoea, bitter taste in mouth, blood in vomit.

daffodill
(Wikipedia) Toxin: lycorine Parts: Concentrated in the bulb but also present in stems and leaves.  Indications: Bulbs: Can be fatal. Nausea, vomiting, and diarrhoea. Stems: headaches, vomiting, and blurred vision. 

four oclock

(N.C State U:) Toxin: not understood Part: seeds, roots primarily, leaves "suspect" Indications: Stomach pain, nausea, vomiting, diarrhoea; handling of the roots may cause dermatitis. 

foxglove
(Wikipedia:) Toxin: digitoxin Part: Leaves, flowers and seeds.  Indications: Can be fatal. Low pulse rate, nausea, vomiting, uncoordinated contractions of different parts of the heart, leading to cardiac arrest and finally death. 

horsetail

Wikipedia: Toxin: Thiaminase Parts: all  Indications: Edema, loss of limb coordination, slowed heart-rate or cardiac irregularity. 

hydrangea
( U. Penn School of Veterinarian Medicine ) Toxin: Cyanogenic glycosides Parts: all parts, especially the leaves. Indications: Can be fatal. Excitement, general muscle tremors, dyspnea, salivation, defecation, urination followed by clonic convulsions and death. 

Japanese/Chinese lantern (Physalis alkekengi)

Canadian Biodiversity Information Facility) Toxin: Solanin Parts: Ripe berries are safe to eat, but all other parts, especially unripe berries, are toxic. Indications: diarrhoea, gastroenteritis, fever, and a scratchy throat within several hours following ingestion. 

lily of the valley
(Wikipedia:) Toxin: 38 different cardiac glycosides Part: all parts of the plant are highly poisonous, including the red berries.  Indications: Can be fatal. Abdominal pain, vomiting, reduced heart rate. 

nicotiana (flowering tobacco)
(North Carolina State U.) Toxin: Nicotine, other alkaloids Parts: all, especially leaves and stems.  Indications: Can be fatal. Vomiting, diarrhoea, slow pulse, dizziness, collapse, and respiratory failure. 

nightshade

(U.S. Federal Forestry Service) Toxin: Solanine Parts: Unripe berries have the highest concentration of toxins, followed by vegetative tissue, then ripe berries. Indicators: Can be fatal. In large doses, slow heart, reduced body temperature,vertigo, delirium, convulsions.
Death is possible if large quantities of unripe berries are ingested. 

peony
ASPCA) Toxin: Paeonol Parts: Leaves and stems. Flower petals are used as garnish and flavouring.  Indications: vomiting and diarrhoea.

rhodos and azaeleas

(Commonwealth of PA/Department of Agriculture)  Toxin: Andromedotoxins (grayanotoxins), water-soluble diterpenoid compounds.  Parts: Leaves and flower nectar  Indications: Can be fatal. Salivation, burning sensation in the mouth. Emesis, diarrhoea, muscular weakness and impaired vision. Bradycardia, hypotension (caused by vasodilation) and atrioventricular block are serious cardiovascular effects that may be lethal. Dyspnea, depression, and prostration develop, and death may occur within 1-2 days. Aspiration pneumonia can develop secondary to emesis. 

sweet peas

(Enyclopedia Britannica blogs) Toxin: Lathyrogens, aminoproprionitrite, glycosides and phenols Parts: All, especially flowers and seeds.  Indicators: in large amounts, paralysis, laboured breathing and convulsions.

indoor

dieffenbachia
(Wikipedia:) Toxin:  raphides Parts: All  Indications: oral irritation, excessive drooling, and localised swelling. 

English ivy (Hedera helix)
( U. Penn School of Veterinarian Medicine ) Toxin:  hederin Parts: black (i.e. ripe) berries, leaves  Symptoms: a purgative that produces local irritation, excessive salivation, nausea, excitement, difficulty in breathing, severe diarrhoea, thirst, and coma.

poinsettia
( Mayo Clinic) Toxin:  Parts: All  Indications:  itchy rash, stomach ache, vomiting and/or diarrhoea. Also, allergic reaction and eye irritation, both caused by the latex-like sap.

pothos
(Wikipedia:) Toxin: insoluble raphides Parts: all  Indications: oral irritation, vomiting, and difficulty swallowing.

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( ) Toxin: Parts: Indications:  'cut flower alert' can be fatal