General Characteristics:
* Leaves: Usually alternate, simple, and often have a toothed or serrated margin. They can be lanceolate, oval, or round, and are typically green but can have various shades depending on the species.
* Stems: Can be upright, trailing, or climbing, depending on the species. Stems can be hairy or smooth, and may be green or reddish-brown.
* Flowers: Lobelia flowers are the most distinctive feature. They are usually small and tubular, with a two-lipped corolla (upper lip is often divided into 2 lobes and the lower into 3 lobes). They come in various colors, including blue, purple, red, pink, white, and yellow.
* Fruit: Lobelia produce small capsules containing numerous seeds.
Specific Examples:
* Cardinal Flower (Lobelia cardinalis): Showy, upright plant with bright red flowers.
* Blue Lobelia (Lobelia siphilitica): Upright plant with vibrant blue flowers.
* Indian Tobacco (Lobelia inflata): Erect, hairy plant with small, pale blue or white flowers.
* Trailing Lobelia (Lobelia erinus): Low-growing, trailing plant with small, colorful flowers.
Beyond the Basics:
* Size: Lobelia plants range in size from tiny annuals to tall perennials.
* Growth Habit: Some species are compact and bushy, while others are trailing or climbing.
* Leaf Texture: Leaves can be smooth, hairy, or even woolly.
It's important to note that these are just general characteristics. To learn about the specific physical traits of a particular lobelia species, you should consult a plant guide or website.
