In botany

Botany

Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

, a staminode is an often rudimentary, sterile or abortive stamen

Stamen

The stamen is the pollen producing reproductive organ of a flower...

. This means that it does not produce pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

. Staminodes are frequently inconspicuous and stamen-like, usually occurring at the inner whorl of the flower, but are also sometimes long enough to protrude from the corolla.
Sometimes, the staminodes are modified to produce nectar, as in the Witch Hazel (Hamamelis).

Staminodes can be a critical characteristic for differentiating between species, for instance in the orchid genus Paphiopedilum

Paphiopedilum

The paphiopedilums – often abbreviated Paph and colloquially known as paphs in horticulture – are flowering plants in the orchid family . It contains about 80 accepted species nowadays, some of which are natural hybrids...

, and among the penstemon

Penstemon

Penstemon , Beard-tongue, is a large genus of North American and East Asian plants traditionally placed in the Scrophulariaceae family. Due to new genetic research, it has now been placed in the vastly expanded family Plantaginaceae...

s.

In the case of Cannas

Canna (plant)

Canna is a genus of nineteen species of flowering plants. The closest living relations to cannas are the other plant families of the order Zingiberales, that is the gingers, bananas, marantas, heliconias, strelitzias, etc.Canna is the only genus in the family Cannaceae...

the petals are inconsequential and the staminodes are refined into eye-catching petal-like replacements.