152 



MISCELLANEOUS PUBLICATION 1271, U.S. DEPARTMENT OF AGRICULTURE 



.14 



.20 



.26v Wiluna a . 



115 



124 



133° 



142° 



Figure 1. — Australian distribution of Eremophila gilesii 

 F. Muell. Data provided by Herbaria of mainland Aus- 

 tralia (excluding Victoria). Dots represent location of 

 specimens and have no relation to plant density. Rain- 

 fall isohyets for 250 and 500 mm. are indicated. 



Observations of the phenology and leaf growth 

 of E. gilesii were made on the Charleville Ex- 

 perimental Reserve. The study area (30 m. by 30 

 m.) was fenced to provide it with a o'-m. inter- 

 nal and 10-m. external buffer zone. Plant density 

 within the plot was determined from randomly 

 placed quadrats. Phenology observations were 

 obtained for 3 bushes in each of 4 height classes 

 (0 to 7.5, 7.5 to 22.5, 22.5 to 45, and >45 cm.) 

 at weekly intervals during active growth and bi- 

 weekly when there was little apparent growth. 

 Single twigs were tagged with plastic labels near 

 the apex of each plant (active shoots) and in the 

 lower third of its height (senescent shoots). At 

 each reading, total number of leaves, buds, flow- 

 ers, and fruits above every permanent tag were 

 recorded. Adequate sampling of reproductive 

 phases was ensured by also tagging a large 

 branch on each bush on which bud, flower, and 

 fruit number alone were counted. Readings were 

 made over a 12-month period from November 

 1969. 



Soil moisture was determined gravimetrically 

 each fortnight in the internal buffer area of the 



plot, the number of samples varying from 4 to 

 10, depending on time since last fall of rain. 

 Rainfall was recorded in a gauge placed in the 

 center of the plot, while temperature records 

 were obtained from a Commonwealth Meteoro- 

 logical Station situated 500 m. distant. 



Germination studies were made in both the 

 field and the laboratory. Fruit density on the 

 ground was determined on the phenology plot, 

 and the number of fruits germinating in March 

 and September 1970 was recorded along tran- 

 sects placed across the plot. Within these tran- 

 sects, 50 seedlings were marked with colored pins 

 after each germination event and their subsequent 

 survival followed. 



In November 1969 about 40.000 fruit were 

 collected from bushes in the stud}^ areas. These 

 were presumably produced following 70-mm. rain 

 in March 1969. After collection, the fruits were 

 mixed and divided into two equal portions. One- 

 half was stored at room temperature in a dry 

 cabinet in the laboratory. The remaining fruit 

 were placed in fiberglass mesh bags (0.25m. 2 ) in 

 the phenology plot to be weathered under natural 

 conditions. The fruits in each bag were restricted 

 to a single layer and each was in close contact 

 with the soil surface. After 6 months and at ap- 

 proximately 4-month intervals thereafter, ger- 

 mination and ovendry weight of weathered and 

 laboratory stored fruit were recorded. 



Field observations suggested that maximum 

 and not minimum temperatures could be limit- 

 ing germination. To confirm this and to estimate 

 a suitable temperature at which to test the weath- 

 ered fruits, germination studies were made in a 

 controlled environment cabinet with fruit ob- 

 tained from the soil surface in an E. gilesii stand. 

 The age of these fruits was not known but was 

 believed to be more than 3 years. Germination 

 is negligible from unweathered fruit and it is 

 impossible to remove the soft seeds enclosed in 

 the hard woody pericarp without damaging the 

 embryos. 



Eight replicates of 100 fruits were placed in 

 petri dishes on two layers of filter paper kept 

 moist with distilled water. The fruits were exposed 

 to constant temperatures in darkness at 10°, 15°, 

 25°, 35°, and 40° C. Germination was recorded 

 at daily intervals for 14 days. 



