Solanaceae.
The Nightshade or Potato Family has 90 to 98 genera and around 2700 species
with almost half in one genus – Solanum.
They are found worldwide but most are from South and Central America.
South East Queensland has 15 genera with around 77 species.
The family is divided into subfamilies and tribes.
Many are grown for food (potato, tomato, chilli and eggplant) or for the flowers
(Petunia, Schizanthus, Brunfelsia and Cestrum).
With such a huge family there is a large range of features.
Below are the most commonly seen ones.
They can be herbs, shrubs, trees, vines or lianas (woody vines).
Leaves are alternate but may be sub-opposite towards the branch ends.
Most are spirally arranged.
They usually have petioles although in some it is very short.
A few have the leaves converted into spines.
There are no stipules and stellate hairs are often present.
The blade can be simple or compound (ternate with 3 leaflets or pinnate).
Venation is pinnate with cross venules.
Inflorescences are a solitary flower or a cluster.
They are terminal, axillary or occasionally opposite the leaves.
The majority of flowers are small or medium in size, bilaterally symmetric and bisexual.
There is no hypanthium but there is usually a hypogynous disc.
Typical flowers have parts in 5’s.
There are 5 (rarely 3 – 9) sepals with their bases fused into a tubular or bell-shaped calyx.
The sepal lobes are shorter than the tube.
The calyx persists into the fruit and sometimes continues to grow.
The 5 (3 – 9) petals also have their bases fused.
The corolla can be tubular, or bell, urn or funnel-shaped.
There are 5 (rarely 3 to 8) stamens but 1 or 3 may be reduced to staminodes.
Stamens, with thread-like or flattened filaments, are opposite the sepals.
Of the same or different lengths, they can insert anywhere down the tube.
The anthers are dorsi or basi-fixed and open via apical pores, small terminal slits
or long longitudinal slits.
In some genera the tips of the anthers touch forming a tight central ring.
The superior ovary has 2 carpels and 2 locules (sometimes 3 to 5 if divided by false septa).
It lies slightly off centre.
There are 1 to many ovules with axile placentation in each locule.
The single style has a simple capitate stigma or a 2-lobed one.
The fruit are berries, capsules that are mostly septicidal or occasionally drupes.
There are usually 2 chambers with flat, round seeds about 3 mm across.
J.F.
