Cardinal flower, Lobelia cardinalis
 
Striking red flowers are a favourite of humans and hummingbirds alike.
Cardinal flowers are a showstopper with their bright red spikes blooming from July to September. The plant has a flat basal rosette and a 90cm to 1.20 m tall stalk that bears the flowers.

Ecology:
Scarlet red signals to the ruby-throated hummingbirds that the flowers contain a lot of nectar. The very long tubular flower shape is perfectly formed so that when the hummingbird's long beak reaches the nectar, the flower's anther can powder the little bird's forehead with pollen. What a beautiful example of co-evolution. 
Cardinal flowers are larval host plants for different species of moths.
Birds eat their tiny seeds.
 
Growing conditions:
In the wild, cardinal flowers grow along streams, ditches, and marshes, thriving in moist to wet conditions in sunny to partially shaded locations. However, they can do well in regular garden settings if we provide watering during the driest times.   
 
Since lobelias are short-lived perennials, the plants will produce many seeds to ensure they can replenish the mother plants. Therefore, it is a good idea not to mulch around lobelias and to scratch the soil lightly to mimic disturbance, so that the seeds have good contact with the soil to create ideal conditions for germination.