| General Information |
|
| Distribution | A genus of about 160 species of tropical and subtropical America, with a few species in tropical Asia and Africa.
|
|
|
|
Habit
|
Erect perennial herbs or shrubs, sometimes somewhat scandent or prostrate, usually scabrous or hispid, sometimes tomentose; stems quadrangular, often with stout prickles.
|
Leaves
|
Leaves decussate or ternate, often rugose, margins usually dentate or serrate, petiolate.
|
Flowers
|
Flowers in dense, usually axillary, cylindrical, indeterminate spikes or heads, each flower subtended by an oblong to lanceolate or ovate bract; calyx small, membranous, truncate or sinuate dentate; corolla slightly irregular, red, yellow, purple, blue, or white, salverform; stamens 4, in 2 pairs, inserted near middle of and included in corolla tube; ovary 1-carpellate, 2-celled, ovules 1 per cell; style usually short; stigma thick, oblique or nearly lateral.
|
Fruit
|
Fruit drupaceous, 2-celled or splitting into 2 pyrenes, exocarp usually fleshy at maturity, rarely dry, endocarp hard.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
