Hwang and Conran, Seedling characteristics (Casuarinaceae) 
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published description of its seedlings by Burger (1972). Seedling data for Gymnostoma 
australianum L. Johnson were obtained from plants grown from seeds collected at 
Noah Creek (Qld) by Dr D.C. Christophel and used in a study by Prider (1998). 
The seedling characters and their states were recorded as follows: 
(1) Primary roots red (1) or white to yellowish (0). 
(2) Cotyledon orientation in relation to the stem apex (Fig. la): level (0), ascending (1) 
or descending (2). 
(3) Cotyledon apex shape (Fig. lb): rounded (0), obtuse (1), acute (2). 
(4) Base of the cotyledons (Fig. lc): not markedly constricted (0), constricted (1), 
petiolate (2). 
(5) Cotyledon shape in cross-section (Fig. Id): flat (0), slightly convex (1), convex (2). 
(6) Colour of senescing cotyledons: yellow to light brown (0) red purple to dark rust- 
red (1). 
(7) Cotyledons pubescent: absent (0), present (1). 
(8) Number of axillary branchlets developing in the cotyledons. 
(9) Cotyledonary axillary branchlets: only developing after those of the primary stem 
(1) ; developing at the same time as the primary stem (0). 
(10) Epicotyl-base colour: green to yellow (0) or red to purple (1). 
(11) Primary shoot orientation (Fig. le): erect (0), slightly curved (1), strongly curved 
(2) or recurved/curled (3). 
(12) Primary branching (Fig. If): simple (0) or compound (1). 
(13) Node number on the main shoot at which branching first occurs (Fig. lg) 
excluding the cotyledonary node. 
(14) Axillary branch supression zone (Fig. lh): absent (0); present (1). 
(15) Primary stem: developing normally (0); suppressed and replaced by cotyledonary 
or basal lateral shoots (1). 
(16) Lateral branchlets (Fig. li): strongly curved (1); or straight (0). 
(17) Number of teeth primary shoot node 15. 
(18) Tooth bases on lateral branchlets (Fig. lj): imbricate (1); valvate (0). 
(19) Lateral branch tooth apices (Fig. Ik): closely appressed (0); or with loosely 
attached, spreading, or divergent apices (1). 
(20) Seedling growth form: stems jointed but without obvious microphyll-like 
protrusions (0); strongly resembling Lycopodium shoots and having the appearance of 
bearing microphylls (1). 
Results 
The results characters are summarised in Table 1. 
The primary root (character 1) was red in Gymnostoma and the majority of Casuarina 
and Allocasuarina sects Allocasuarim, Cylindropitys, Nannopitys, and Trichopitys, while 
Allocasuarina sects Dolichopitys, Echinopitys and Oxypitys had yellow- or white-rooted 
seedlings although both colour types were represented in most sections. 
The cotyledon orientation (2) was horizontal in the majority of the taxa examined, 
except for A. acutivalvis and A. paradoxa where it was descending, and A. thuyoides 
where it was ascending. Tire cotyledon apex (3) was usually rounded, although it was 
obtuse in four species of Allocasuarina, mostly in sect. Cylindropitys, and acute in four 
other species of Allocasuarina. Cotyledon bases (4) were distinctly petiolate only in 
Gymnostoma, not only for G. australianum, but also in seedlings of G. vitiense which 
were grown for this study but which did not survive beyond the cotyledon stage. The 
base of the cotyledons was markedly constricted in all Casuarina spp., but four species 
of Allocasuarina in different sections. Cotyledon shape in cross-section (5), although 
