Little bluestem

Schizachyrium microstachyum
Grass
Alternate
Simple
Cream
Green

Little Bluestem is a densely tufted perennial grass growing to more than a metre tall, although it is most often seen growing to about 60 cm. It is a very distinctive grass, especially following flowering when it produces masses of feathery seeds. 

Common names 
Also known as: Little blue stem,
Family 
Poaceae
Deciduous 
No
Flowering time 
Spring and summer
Native/Exotic 
Exotic
Origin 
Native to large parts of Central and South America, from Mexico to Uruguay,
Notifiable 
No
State declaration 
Nil
Council declaration 
SIL – Special Investigation List
Known distribution 

This species has already become naturalised in many parts of south-eastern Queensland. It is most prominent in the eastern suburbs of Brisbane and in parts of the Moreton Bay Regional Council area, and has also been recorded from the Gold Coast area. During early 2011 Little bluestem has been reported from at least three sites in Brisbane, two of which are conservation reserves (i.e. in the Brisbane Koala Bushlands at Burbank and the Chermside Hills Reserve). Currently Little bluestem is restricted to the wetter coastal districts of south-eastern Queensland, but in its native range in America it is quite widespread and is found in many inland districts. 

Habit 

Little bluestem is an upright tufted grass usually growing 60-100 cm tall, but may sometimes reach up to 1.5 m in height. Its upright stems are slender, often somewhat oval in cross-section, and have upwardly projecting branches.

Impact and control methods 

Little bluestem is a particular threat to natural grassland and open woodlands that have a grassy understorey. Like many exotic weeds, it has the potential to form dense infestations that replace native species in the understorey of these plant communities and prevent
their regeneration. It may also replace more palatable grasses in pastures, thereby reducing pasture productivity.

Stem and leaves 

Little bluestem is an upright tufted grass usually growing 60-100 cm tall, but may sometimes reach
up to 1.5 m in height. Its upright stems are slender, often somewhat oval in cross-section, and have
upwardly projecting branches. New stems are produced each year from the long-lived base of the
plant. The alternately arranged leaves are long and narrow (up to 40 cm long and 3-8 mm wide),
mostly hairless, and have a stem-clasping sheath at the base.

Flowers and fruits 

The seed-heads are produced during late spring and summer, and are densely clustered at the top of the stems. They are made up of numerous small flowering branches (about 25 mm long), each contained inside a leafy bract (13-18 mm long) that is coiled inwards. These flowering braches are jointed and bear several small flower spikelets, some of which emerge from the top of the leafy bract as they mature. The parts of the flowering branches between the joints, and the flower spikelets themselves, are covered in whitish hairs which give the mature seed-heads a very feathery appearance. They also bear a slender bristle-like structure (i.e. awn) 11-16 mm long. 

Reproduction and dispersal 

When mature, the small flowering branches break apart into segments. Each of these feathery segments contains a small seed, hidden inside the older parts of the flowering spikelets. Because of their light and feathery nature, they are easily spread about by the wind.
They may also be dispersed by water, vehicles, mowing equipment and in contaminated soil.

Similar species 

It superficially resembles Whisky Grass (Andropogon virginicus), a related species also from South America. While the leaves and stems of the two species are similar, the flowers and seeding heads of Little Bluestem are more densely clustered than those of Whisky Grass and have smaller individual seeds.