Yellow Sweet Clover (melilotus offcinalis): Without a close-up of the flower, we can't be sure about this but the plant looks similar to this common wildflower or weed. It has sweet hay-scented foliage. It is commonly found growing in fields.
Introduced Sage (salvia pratensis): Salvia pratensis (meadow clary or meadow sage) is a species of flowering plant in the family Lamiaceae, native to Europe, western Asia and northern Africa. The specific epithet pratensis refers to its tendency to grow in meadows. It also grows in scrub edges and woodland borders. https://en.wikipedia.org/wiki/Salvia%20pratensis
Red Clover (trifolium pratense): Your plant is a red clover, native in Europe; is a common lawn weed or a wildflower, depending on its use and your point of view. It is a common winter cover crop and a fun plant to have. If you have this distinctive leaf clover in your lawn or flowerbeds and want to remove it, do it before it blossoms and sets seeds.
Christmasbush (senna bicapsularis): "Cassia bicapsularis" and "Cassia emarginata" redirect here. These taxa have been used for other plants too; see below. Senna bicapsularis is a species of the legume genus Senna, native to northern South America, from Panama south to Venezuela and Colombia, and also the West Indies. It is naturalised and invasive in several coastal areas in the tropics, including the Galápagos Islands and New Caledonia. Common names include rambling senna (formerly…