Tariq Husain has written:

'Genus pedicularis L. (Scrophulariaceae) in India' -- subject(s): Classificaiton, Pedicularis, Classification

A betony is a plant of the genus Stachys, especially Stachys officinalis, a herb used in traditional European medicine, or a plant of the genus Pedicularis, also known as the lousewarts.

Clematis vitalba, Pedicularis grandifolia, Canavalia rose, Nelumbo nucifera, Leonurus sibiricus and Heimia salicifolia.

Rhododendron tomentosum and Ledum palustre, some of the plants used in k2 incense, contain poisonous terpenes that affect the central nervous system. First symptoms of overdose are dizziness and disturbances in movement, followed by spasms, nausea, and unconsciousness. The mere smell of the plant may cause headache to some people.

In addition, one or more of the following chemicals is used as the active ingredient in synthetic marijuana:

WH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, RCS-4, RCS-8, AM-694, and AM-2201

All of these chemicals are in the process of being banned, or already banned.

There is a long list, everything from Acacia, Allium, Ambrosia, Anemone, Asparagus, Aster, Baptisia, Betula, Bidens, Brassica, Bromus, Cabomba, Campsis, Capsella, Cardamine, Carduus, Carex, Carya, Cassia, Cenchrus, Centaurea, Cerastium, Cheilanthes, Cirsium, Cicuta, Clematis, Conyza, Coreopsis, Cornus, Coronilla, Cunila, Cucurbita, Cuscuta, Cynodon, Cyperus, Delphinium, Dentaria, Dianthus, Desmodium, Dodia, Dodecatheon, Echinacea, Echium, Ellisia, Elymus, Epilobium, Euonymus, Eupatorium, Euphorbia, Fagus, Fragaria, Galactia, Galium, Geranium, Gerardia, Geum, Hackelia, Helemium, Helianthus, Hordeum, Hesperis, Hibiscus, Houstonia, Hydrangea, Hydrophyllum, Impatiens, Ipomoea, Iris, Iva, Juncus, Justicia, Krigia, Lactuca, Lechea, Lepidium, Linum, Liatris, Lobelia, Lonicera, Lotus, Lupinus, Ludwigia, Lyonia, Magnolia, Malaxis, Malva, Manfreda, Medicago, Melanthium, Mentha, Mimulus, Monotropa, Nepeta, Nuphar, Ocimum, Opuntia, Oxalis, Palafoxia, Panax, Pedicularis, Penthorum, Phlox, Phryma, Plantago, Poa, Physalis, Polygonum, Portulaca, Potentilla, Psoralea, Quercus, Ranunculus, Raphanus, Rhus, Robinia, Rosa, Rotala, Rumex, Sabatia, Sanicula, Sassafras, Scilla, Scirpus, Senecio, Sedum, Setaria, Sium, Solanum, Solidago, Specularia, Spiraea, Spiranthes, Talinum, Tanacetum, Thlaspi, Tipularia, Tragia, Trichostema, Trifolium, Trillium, Triticum, Uniola, Vaccinium, Veratrum, Verbascum, Vernonia, Viburnum, Vitus, Viola, Yucca, to Zizia, and nearly countless others that I don't have time to mention.