Spines

The presence or absence of spines: sharp, stiffened structures formed by the modification of a plant organ, e.g. a lateral branch, leaf vasculature or a stipule.

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Spinescent branchlet apices

Branchlets, generally short lateral shoots, terminate in a sharp point. These are often leafy, but may be apparently leafless, appearing as a short, single spine arising from the leaf axil (e.g. Bossiaea spinescens; Mirbelia rhagodioides).

Prickles on stem

Hard, pointed outgrowths arising from the stem (thorns). These can be cleanly snapped-off, sharing no vascular connection with the stem (e.g. Daviesia euphorbioides).

Pungent leaves

The leaf apex terminates in a stiff point (generally capable of piercing skin) and/or several spines may arise on the margin of the leaf (e.g. Chorizema ilicifolium, Podolobium ilicifolium). These are usually associated with major veins (i.e. midrib and secondary venation). In some cases (e.g. Daviesia genistifolia) the leaf/phyllode is terete, entirely stiffened and apparently reduced to a spine.

Pair of spines

Spines arising in pairs from the base of leaves (e.g. Templetonia aculeata). These are modified stipules (leaf appendages), sometimes persistent beyond the life of the leaf (as in Robinia pseudoacacia).

Absent

The plant lacks spines of any kind.