1. (n.) A genus of leguminous plants (herbs, shrubs, or trees) of many species, most of which have purgative qualities. The leaves of several species furnish the senna used in medicine.

2. (n.) The bark of several species of Cinnamomum grown in China, etc.; Chinese cinnamon. It is imported as cassia, but commonly sold as cinnamon, from which it differs more or less in strength and flavor, and the amount of outer bark attached.

acacia ailanthus alder alligator pear allspice almond apple apricot ash aspen atramentous avocado balsa balsam banyan bass basswood bay bayberry beamless beech beechwood betel palm birch black black as coal black as ebony black as ink black as midnight black as night black race blackness buckeye burl butternut buttonwood cacao caliginous candleberry cashew cassia catalpa charcoal cherry chestnut chinquapin cinnamon citron clove coal coal-black coaly coconut cork cork oak crow cypress dark dark as night dark as pitch darkling darkness darksome deep black dogwood ebon eclipsed elder elm eucalyptus fig fir frankincense grapefruit guava gum gumwood hawthorn hazel hemlock henna hickory holly hop tree horse chestnut ink ink-black inkiness inky ironwood jet jetty juniper kumquat laburnum lancewood larch laurel lemon lime linden litchi litchi nut locust logwood magnolia mahogany mango mangrove maple medlar melanism midnight mountain ash mulberry night night-black night-clad night-cloaked night-dark night-enshrouded night-filled night-mantled night-veiled nigrescence nigritude nigrous nutmeg oak obfuscated obscure obscured occulted olive orange palm papaw papaya peach pear pecan persimmon pine pistachio pitch pitch-black pitch-dark pitchy plane plum pomegranate poplar quince raffia palm rain tree raven raven-black rayless redwood sable sandalwood sassafras senna sequoia sloe sloe-black sloe-colored smoke smut soot spruce starless sumac sunless sycamore tangerine tar tar-black tarry teak tenebrious tenebrose tenebrous tulip tree unilluminated unlighted unlit walnut willow witch hazel yew