Macrozamia heteromera

Macrozamia heteromera is a species of plant in the family Zamiaceae. It is endemic to New South Wales, Australia.It is found in dry sclerophyll woodlands. Its height is usually below 1 meter as it is a low trunked cycad. The M. Heteromera can be distinguished from the rest of the Macrozamia Genus by its mid-green, narrow, usually divided pinnae and divided seedling pinnae. 
Discovery.
The Macrozamia Heteromera was first discovered by Australian Botanist Charles Moore during a journey in which he discovered leaf specimens of the Heteromera . However, as Moore was unable to collect any of the fruit, he did not have enough information to provide a thorough description of the plant. It was not until the year 1882 where Moore’s assistant Mr. Betche had collected adequate specimens of the leaves and fruit of the Heteromera which upon receiving in 1883 was named by Moore . At the time, Moore had believed that there were two other variations of the M. Heteromera . He named the two variants glauca and tenuifolia. The glauca was distinguishable by its longer leaves that lacked the rigidity and was always glaucous and glabrous. The tenuifolia’s leaves were more rigid of a dark green colour. Furthermore, its pinnae forked twice and was bright red at the base. However, after a small revision in 1998 by David L Jones, the glauca and tenuifolia variants became recognised as their own species under the M. Heteromera complex. The glauca variant became known as the Macrozamia glaucophylla and the tenuifolia became the Macrozamia polymorpha . 
Description.
The Macrozamia Heteromera is a small low-trunked cycad that often grows to a height of less than 1 meter. The stem grows up to 15 to 25cm in diameter and is light green in colour. The leaves can grow to around 50 to 90 cm long and are composed of up to 60 to 100 pinnae of a mid-green colour that branches into two which is a feature that helps to distinguish this from other species within the same genus . The number of cones is very irregular, a feature of the Macrozamia species. However, on average, male plants can have up to 4 cones that are curved, and females have 1 to 2 of an ovoid shape. Male cones typically range from 12–20 cm long and up to 5 cm in diameter, females range from 10–25 cm long and are up to 12cm in diameter. Inside the cones are sacrotesta red seeds around 26-31 mm long and 20–25mm wide .
Distribution and habitat.
Occurring on sandy, stony and infertile siliceous soils over acid volcanics and often in dry sclerophyll woodlands, Macrozamia Heteromera is an endemic species to New South Wales. It can be found in north-western New South Wales in the Warrumbungle Mountains and further south west.
Ecology.
The seeds from this cycad are edible after proper preparation. The first reported poisoning from this cycad occurred in 1916 within the Coonabarabran district. Some fatalities of cattle had been reported and those affected had staggered and lost control of their hind quarters . It was previously believed that the Heteromera had caused a mass sheep poisoning in the Coonabarabran in 1929 wherein sheep had eaten the seeds of the cycad for an hour unmonitored . This resulted in 5 sheep dying within 18 to 20 hours and death continuing for 3 weeks resulting in 2,200 sheep dying out of 6,000. However, it was later confirmed that the poisoning was caused by Macrozamia diplomera via a veterinary report. Farmers have used terms such as ‘zamia staggers’, ‘zamia rickets’ or ‘zamia wobbles’ to describe the symptoms due to cattle consuming Macrozamia seeds and leaves. Farmers had coined the term ‘sheep nuts’ for M. Heteromera’s seeds. 