Eucalyptus species- Releases too much eucalyptol, which is toxic in moderate doses, to be usable for smoking
Camphor- Contains the compound camphor which is harmful to eat in amounts that will be imparted from smoking.
Oleander- All parts of oleander are toxic due to the cardiac glycosides oleandrin, nerin, and digitoxigenin.
Rhododendron- All parts contain highly toxic grayanotoxins.
Yew- Contains the overwhelmingly toxic alkaloids known as taxines.
All Laburnum Species (They contain cytisine and other toxic alkaloids)
Any species that has a high Latex content in its wood, as the latex burns to produce various carcinogens.
liquid amber, mangrove, poisonous walnut, tambootie (Need to be checked, but have been listed) ¹⁾

Under this envelope all species of conifers are generally listed. The ongoing logic is that the softer wood and high resin content of conifers makes for wood that burns poorly and smoke that is off flavored, bitter, and unpleasant.

Elm- Has dense wood that also holds moisture, this makes for poor smoking properties ²⁾, but has also been described as a good wood for smoking such things as chicken, and that is produces a light smoke that has a vegetal flavor to it. ³⁾
Sycamore- Commonly listed as unusable, but also referenced as a fine smoking wood with an unusual earthy-mushroomy flavor and is recommended for pork.⁴⁾ Likely has poor working qualities and is listed as a fast burning wood when used for fires. ⁵⁾

Using wood that has been fully dried and seasoned is also recommended against. The working properties of this kind of wood can be inconsistent and often the wood will burn unevenly because of the water content.

Lumber
Chemically treated lumber
Wood with paint or stain on it
Wood with signed of mold, spalting, or darkening

ACACIA - these trees are in the same family as mesquite. When burned in a smoker, acacia has a flavor similar to mesquite but not quite as heavy. Is a very hot burning wood.
MESQUITE - Strong earthy flavor. Good with beef, fish, chicken, and game. One of the hottest burning woods.
KIAWE- Hawaiian Wood traditionally used for smoking.

PECAN - Sweet and mild with a flavor similar to hickory. Tasty with a subtle character. Good with poultry, beef, pork and cheese. Pecan is an all-around superior smoking wood.
HICKORY - Most commonly used wood for smoking–the King of smoking woods. Sweet to strong, heavy bacon flavor. Good with pork, ham and beef.
WALNUT - ENGLISH and BLACK - Very heavy smoke flavor, usually mixed with lighter woods like almond, pear or apple. Can be bitter if used alone. Good with red meats and game.
Butternut-

ORANGE, LEMON and GRAPEFRUIT - Produces a nice mild smoky flavor. Excellent with beef, pork, fish and poultry.

APPLE - Very mild with a subtle fruity flavor, slightly sweet. Good with poultry (turns skin dark brown) and pork.
CRABAPPLE - Similar to apple wood.
PEAR - A nice subtle smoke flavor. Much like apple. Excellent with chicken and pork.

CHERRY - Mild and fruity. Good with poultry, pork and beef. Some List members say the cherry wood is the best wood for smoking. Wood from chokecherry trees may produce a bitter flavor.
ALMOND - A sweet smoke flavor, light ash. Good with all meats.
OTHER PURNUS WOODS - APRICOT, PLUM, PEACH, NECTARINE - Great on most white or pink meats, including chicken, turkey, pork and fish. The flavor is milder and sweeter than hickory.

COTTONWOOD - It is a softer wood than alder and very subtle in flavor. Use it for fuel but use some chunks of other woods (hickory, oak, pecan) for more flavor. Don't use green cottonwood for smoking. ALDER - Very delicate with a hint of sweetness. Good with fish, pork, poultry, and light-meat game birds.
Box Alder- similar to maple. ⁶⁾ MAPLE - Smoky, mellow and slightly sweet. Good with pork, poultry, cheese, and small game birds.
ASH - Fast burner, light but distinctive flavor. Good with fish and red meats.
BIRCH - Medium-hard wood with a flavor similar to maple. Good with pork and poultry.

GRAPEVINES - Tart. Provides a lot of smoke. Rich and fruity. Good with poultry, red meats, game and lamb.

LILAC - Very light, subtle with a hint of floral. Good with seafood and lamb.

MULBERRY - The smell is sweet and reminds one of apple.
Osage Orange- Hard, High burning with a lot of smoke, used as a charcoal replacement. ⁷⁾

OAK - Heavy smoke flavor–the Queen of smoking wood. RED OAK is good on ribs, WHITE OAK makes the best coals for longer burning. All oak varieties reported as suitable for smoking. Good with red meat, pork, fish and heavy game.

Sassafras- A controversial wood to use because of the safrole content. Will impart safrole into the smoked food. ⁸⁾

Mango- Similar to apple in properties with a mild sweet fruity flavor.
Guava- I imagine most none Eucalypteae members of the myrtle family are fine

Palo Santo- Bursera graveolens
Avocado- medium in intensity. Should have a spicy quality because of the iso-euginol content
California bay- branches have long been used as skewers for cooking meats as well, smoke may cause headaches.
Bay laurel- Long used for cooking foods and making skewers for foods
Pimento Wood- Includes both allspice and Caribbean pimento, described as a sweet smoke ⁹⁾

CARROTWOOD, , MADRONE, MANZANITA, OLIVE, BEECH, FIG, GUM, CHESTNUT, HACKBERRY, PIMIENTO, PERSIMMON, and WILLOW.

There is a great deal of contradictions, repeated and uncited information between sources, and poorly explained reasoning as well in this topic. Very little of the things being said are supported or explained in ways that display clear reasoning. This is so bad that there is even an article that says terpenes are a danger to consume? ¹⁰⁾

The fullest list I could find of species that can be used for smoking- ¹¹⁾

Descriptions of the flavor profiles of various woods ^{12) 13) 14)}