Journal of the Royal Society of Western Australia, 87(4), December 2004 
0 50 100 150 200 
Days after anthesis 
Figure 1. Fresh (thick solid line) and dry (dashed line) weight of 
fruit, and dry weight of seeds (thin solid line) during annual 
fruit development of H. erinacca and H. trifurcata. Data represent 
mean (± SE) from 50 fruits per species. 
Results 
Hakca erinacea fruits took 180 days to reach maturity, 
with wood formation in the fruit walls commencing 120 
days after anthesis (Fig. 1). The similar sized H. trifurcata 
fruits took 215 days to reach maturity, with wood 
formation initiated after 110 days (Fig. i). H. trifurcata 
seeds were slightly larger (16.4 ± 2.4 mg dry weight) 
than those of H. erinacea (12.5 ± 2.8 mg), although both 
species had similar final seed-to-fruit weight ratios (0.19; 
based on two seeds per fruit). Seeds were fully formed 
after 154 (H. trifurcata) and 161 (H. erinacea) days of 
development, 40 days after the commencement of fruit 
wood formation. Both species retained chlorophyll in 
their fruit walls during the non-woody ('green') phase of 
development. For H. erinacea, total fruit wall chlorophyll 
content stabilised around 0.24 mg g 1 between 40 to 133 
days (Fig. 2), whereas H. trifircata chlorophyll content 
decreased with an increase in developing fruit size. 
Chlorophyll content of developing fruit was 
approximately one-third of leaves (0.6-0.9 mg g 1 ). 
Chlorophyll was present in the walls of mature H. 
trifircata fruits (0.09 mg g 1 ), but not in the fruit walls of 
H. erinacea. 
Of the five nutrients investigated, the total fruit 
nutrient content (in mg) for H. erinacea was near zero 21 
days after anthesis (N: 0.039; P: 0.0004; K: 0.02; Ca: 0.032; 
Mg: 0.0009). These increased to a maximum 105 days (N: 
I. 18), 120 days (P: 0.017) and 160 days (K: 0.13, Ca: 0.06, 
Mg: 0.02) after anthesis (Fig. 3). For K, Ca and Mg, this 
was approximately 20 days before the onset of fruit wood 
production. Once fruit wood formation had commenced, 
the total nutrient content (in mg) of one H. erinacea seed 
(N: 1.18, P: 0.14, K: 0.11, Ca: 0.18, Mg: 0.05) was less than 
(N, P) or greater than (K, Ca, Mg) the amount present in 
a fully developed seed (Fig. 3). Calculating apparent 
translocation of each nutrient from the follicle as it 
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0.3 
0.2 
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H. erinacea 
Days after anthesis 
Figure 2. Total chlorophyll content of the fruit wall during 
annual fruit development of H. erinacea and H. trifurcata. 
Arrowed-line represents period during fruit development when 
fruit were fleshy and non-woody. Data represent mean (± SE) 
from 5 fruits per species. 
136 
