4 BULLETIN" 5 9, HAWAII EXPERIMENT STATION 
short stalk attached to the perianth throat; the perianth is split on 
the side to release the club-shaped style and stigma, and the ovary is 
covered with fine hairs. (Fig. 2.) The fruit consists of a 2-valved 
leathery exocarp, and the endocarp, which varies in thickness from 
three-thirty-secorids to three-sixteenths inch, is very hard, and the 
surface is undulating to bumpy. The fruit is 1-seeded, usually globu- 
lar, or occasionally 2-seeded, in which case each nut is hemispherical. 
On maturity the exocarp splits, dropping the nut which is 1 to \y± 
inches in diameter. If the nut falls in a damp place, the shell will 
absorb moisture rapidly and crack, and if other conditions are right 
the seed will germinate. (Fig. 3.) 
Macadmnia ternifolia var. integrifolia differs from M. tcmifolia 
in that it is a smaller tree, and has a more spreading top. The leaves 
are usually smaller, each has a petiole about an inch long and a 
rather spatulate blade, and the margins are entire or with very few 
Figure 2. — Macadamia flower : A, Opening perianth ; B, pistil and anthers released ; 
C, interior view of perianth ; D, expanding anthers ; and E, developing ovary 
spines. The flowers are creamy white and are borne in clusters. 
Usually only 2, 3, or 4 flowers of each cluster set fruit. The 
nuts are more nearly spherical, the surface of the shell is smoother, 
and in size they average a little smaller than do those of M. ternifolia. 
The Macadamia tree has various common names. In a large part 
of Australia it is well known as the Queensland nut, and in other 
parts it is called the Australian nut. It is known by still other names 
in different localities in Australia. In Hawaii it is most generally 
called the Macadamia. Walter Hill, the first director of the Brisbane 
Botanical Gardens, is credited with having discovered the nut while 
studying the flora of the Moreton Bay district. It was botanically 
named Macadamia ternifolia in honor of Dr. John Macadam, presi- 
dent of the Philosophical Society, Victoria, Australia. The specific 
name ternifolia has reference to the arrangement of the leaves in 
whorls of three at each node. The genus Macadamia belongs to the 
natural order Proteaceae, as do also the well-known groups of trees 
Waratah, Grevillea, and Hakea. Other species of the genus are 
