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MACROZAMIA MOOREI, A CONNECTING LINK 
BETWEEN LIVING AND FOSSIL CYCADS 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 168 
CHARLES J. CHAMBERLAIN 
(WITH TWELVE FIGURES) 
The greatest cycad centers of the world are the states of Vera 
Cruz and Oaxaca in Mexico and Queensland in Australia, Queens- 
land having three genera, Cycas, Macrozamia, and Bowenia, and 
the Mexican region three genera, Dioon, Ceratozamia, and Zamia. 
As yet no other region has claimed more than two genera. In the 
cycad region of Australia Macrozamia is the dominant genus, and 
its various species range from the northern part of Queensland to 
the southern limit of cycads in New South Wales. In a more 
extended publication the genus and the interrelationship of its 
species will be discussed, but at present we shall consider only a 
single species, Macrozamia Moorei, which presents features of 
unusual interest. The field study was made at Springsure, about 
200 miles west of Rockhampton and almost on the Tropic of 
Capricorn. 
Macrozamia Moorei has a massive cylindrical trunk with a 
splendid crown of leaves (fig. 1). Most of the plants grow in the 
blazing sun, but some are found in the scanty shade of small 
Eucalyptus and other trees. The altitude of Springsure is about 
325 m., but some plants were noticed a few miles east of Springsure, 
perhaps 30 m. lower, and specimens could be seen on the tops of 
the neighboring mountains, perhaps 300 m. higher. 
he trunk is 2-3 m. high in most of the large plants; a few 
reached 5 m. in height, and one specimen, growing in the shade, 
measured 7 m. from the ground to the bud. The diameter of the 
trunk of this specimen was 66 cm., but there is little increase in 
diameter after a plant reaches a meter in height, for such plants 
may be 0.5 m. in diameter, and some plants 3 m. in height, and 
growing in the sun, measured 71 cm. in diameter. 
141) [Botanical Gazette, vol. 55 
