Solanaceae (Asteridae)

 

Family of tomatoes and potatoes

Contents
Size
Distribution
Importance
Morphology
Similar families
Identification

Genera
Atropa
Browallia
Brunfelsia
Capsicum
Chamaesaracha
Datura
Hyoscyamus
Lycium
Lycopersicon
Mandrago
Nicotiana
Petunia
Physalis
Salpiglossis
Schizanthus
Solandrum
Solanum

Sources
Alston & Turner 1963
Cronquist 1981
Heywood 1978

Bot. 3400 Home
 

Contents
Size
Distribution
Importance
Morphology
Similar families
Key

Genera
Atropa
Browallia
Brunfelsia
Capsicum
Chamaesaracha
Datura
Hyoscyamus
Lycium
Lycopersicon
Mandrago
Nicotiana
Petunia
Physalis
Salpiglossis
Schizanthus
Solandrum
Solanum

Sources
Alston & Turner 1963
Cronquist 1981
Heywood 1978

 Contents
Size
Distribution
Importance
Morphology
Similar families
Identification

Genera
Atropa
Browallia
Brunfelsia
Capsicum
Chamaesaracha
Datura
Hyoscyamus
Lycium
Lycopersicon
Mandrago
Nicotiana
Petunia
Physalis
Salpiglossis
Schizanthus
Solandrum
Solanum

Sources
Alston & Turner 1963
Cronquist 1981
Heywood 1978

 

 

Size
The Solanaceae has about 90 genera and 2,800-3,000 species.  The largesst genus, by far, is Solanum.  It has around 1,400 species. 

Distribution
The Solanaceae is a cosmopolitan family, occurring in tropical and temperate regions throughout the world.  Its greatest center of diversity is in central and northern South America, but there is a  secondary center in Australia.  

Shaw lists 18 species for northern Utah, all but 2 of which are introduced. 

Importance
If you like eating, the Solanaceae is an important family.  Solanaceous foods that can be found in our stores include potatoes, tomatoes, peppers of the red, green, yellow, and chili varieties, eggplant, and tomatillos.  Many other members of the family are important foods in South America but, so far as I am aware, the family was not particularly exploited by native peoples in Australia.  This could be my ignorance, or possibly Australian species do not produce edible fruits   

Many species of Solanaceae produce tropane alkaloids that have valuable medicinal properties, but which may also be extremely poisonous. Examples include Atropa (belladonna or deadly nightshade), Datura stramonium (jimson weed), Mandragora offinalis (mandrake), and Hyoscyamus niger(black henbane).  Nicotine is a tropane alkaloid.  It makes a great insecticide. 
The Solanaceae also includes many genera with ornamental species.   These include Browallia, Physalis, Schizanthus, and Petunia.   Other species, often in the same genera, are weeds.   Examples include species of Physalis, Hyoscyamus, and Solanum.  

Morphology
Most members of the Solanaceae are erect or climbing, annual or perennial herbs, but shrubs are not uncommon and there are a few trees.  The leaves vary greatly in shape but are usually simple, although sometimes highly lobed.  They are alternate and never have stipules. 
The inflorescence is generally cymose and axillary, but may be reduced to a single flower.  The flowers are bisexual, usually radially symmetric, and usually 5-merous [Note those "usuallys"].  The calyx is united, at least at the base, and sometimes becomes inflated in fruit.  The corolla is also united but its shape varies from long and tubular to rotate or campanulate.   It is usually radially symmetric, but there are some bilaterally symmetric genera.   There are 5 (rarely 4-8) epipetalous stamens that alternate with the corolla lobes.  The anthers are sometimes touching but are never fused.  The gynoecium consists of a single pistil, usually with 2 locules and numerous ovules.  The fruit is a usually a berry (think of sweet peppers and tomatoes) but quite frequently a dry capsule. 

Similar families
The Convolvulceae differs from the Solanaceae in several non-morphological characters, but the species in northern Utah are all herbaceous vines, whereas the Solanaceae in Utah are erect.  In addition, the Convolvulaceae generally has 2 basal ovules rather than numerous axile to parietal ovules. 
The Scrophulariaceae usually differ from the Solanaceae in having bilaterally symmetric corollas, but there are some bilaterally symmetric members of the Solanaceae and some radially symmetric, or almost radially symmetric, Scrophulariaceae.  Then what?  The Solanaceae has bicollateral vascular bundles.  This means that its vascular bundles have phloem on both the inside and the outside.  Not a character one likes to use in the field.   Fortunately, it is rarely necessary.   The Solanaceae also differs in having oblique ovaries, and you do not really want to have to look for that character either.  

 

 


When the slide scanner is fixed, this panel will contain pictures of solanaceous plants. tropane.GIF (1393 bytes)
Tropane