| ANGOSTURA | -- bark is the bitter aromatic bark of certain South American trees formerly used medicinally to reduce fever (9) |
| CURARE | Black resin obtained from certain South American trees and used medicinally as a muscle relaxant and by South American Indians as an arrow poison |
| WAGENBOOM | From Afrikaans, a tree formerly used to make cartwheels |
| CASSIA | Aromatic bark of a tropical Asian tree that tastes similar to cinnamon (6) |
| OUTRANCE | It is the bitter end when soul at heart is in a state of unconsciousness (8) |
| CHOKECHERRY | Caught with heroin by mistake: going into prison is the bitter fruit |
| RIMU | Native tree formerly called red pine (4) |
| ATROPINE | Poisonous alkaloid occurring in deadly nightshade and related plants, used medicinally to dilate the pupils, stimulate the heart etc. (8) |
| ASPIRIN | Synthetic compound used medicinally to relieve pain (7) |
| FEVERFEW | The strong-scented perennial plant Chrysanthemum parthenium, formerly used medicinally |
| CINCHONA | Genus of South American trees whose dried bark is a source of quinine (8) |
| QUASSIA | Genus of South American trees whose bitter bark and wood has medicinal properties (7) |
| QUILLAIAS | Nurse surrounded by rolls of bark in South American trees |
| PERUVIAN | Certain South American power getting on top of simple uprising about sport |
| LIGNUMVITAE | Wood from tropical American trees of the genus Guaiacum, formerly thought to have medicinal properties (6,5) |
| COPAIBA | Resin from South American trees used in medicines, varnishes etc (7) |
| BRAZILNUTS | Edible seeds of some South American trees |
| SASSAFRAS | Yellowwood tree of the Laurel family, native to the US, whose bark is used for tea and as a medicine (9) |
| NEEM | Large tree of India in the mahogany family whose bark is used to make a tonic (4) |
| INCA | Certain South American Indian |
