| 100% | CASSAVAS | 8 | Plants that are a natural source of cyanide |
| 58% | POTASSIUMIODIDE | 15 | Kelp is a natural source of it |
| 54% | ALE | 3 | Beverage that was a medieval source of nutrition |
| 53% | AIR | 3 | ___-purifying plants, natural source of reducing pollution that was researched by NASA |
| 53% | PINES | 5 | Coniferous trees that are a source of timber |
| 53% | ITASCA | 6 | Lake that is a source of the Mississippi |
| 52% | EGG | 3 | Poultry output that is a healthy source of fat |
| 52% | LIME | 4 | Green fruit that is a good source of vitamin C |
| 52% | FLAX | 4 | Plant that's a source of linen fiber |
| 51% | CROCI | 5 | Flowers that are a source of the anti-inflammatory drug colchicine |
| 51% | ROE | 3 | Fish eggs that are a rich source of omega-3 fatty acids |
| 50% | REDBUSH | 7 | Plant that's the source of a caffeine-free tea |
| 50% | BLIGHT | 6 | Plant disease that is a type of chlorosis |
| 50% | PAROS | 5 | Greek island that was a source of fine white marble in ancient times |
| 50% | BATTERY | 7 | A portable source of power that might be AA or AAA |
| 49% | FUSION | 6 | Mr. ___, gadget from "Back to the Future" that is a source of sustainable energy |
| 49% | THYME | 5 | Bouillabaisse seasoning, that was once considered a source of courage |
| 49% | LAKE | 4 | ___ Victoria, waterbody in the Tanzanian and Ugandan forests that is a source of the Nile |
| 47% | STEM | 4 | Part of plant that is cut off when making a bouquet |
| 46% | VITAMINC | 8 | Nutrient that citrus fruits are a good source of: 2 wds. |
| 46% | YEW | 3 | Tree that was the source of the poison in Christie's A Pocket Full of Rye |
| 46% | UDDER | 5 | Part of a cow that is a source of milk |
| 45% | OLIVETREE | 9 | Plant whose fruit is a source of cooking oil (2 wds.) |
| 45% | ANGORAS | 7 | Wool sources that were the subject of a 2013 PETA exposé |
| 45% | GIBRALTAR | 9 | Strait that is a natural exit in the Mediterranean |
| 45% | MAPLE | 5 | Tree that is known for its fall foliage and as a source of a syrup enjoyed with pancakes |
| 45% | WEEDS | 5 | Plants that are "evicted" from a garden |
| 45% | POTTED | 6 | Plant that is kept in a container |
| 44% | HEATHER | 7 | Plant that was a top-five girl's name in the 1970s |
| 44% | TEAK | 4 | Plant whose name becomes that of a meat product when an s is added to the beginning |