18b. Inflorescences terminal, pseudoaxillary (i.e., regularly borne in only 1 axil at a node), or apparently
pseudoaxillary or lateral due to anisophylly or an undeveloped internode.
18a. Inflorescences not borne at stem apex but regularly axillary (i.e., borne in both axils at a node),
superaxillary, and/or apparently axillary due to regularly produced axillary or lateral short
shoots (i.e., brachyblasts).
stout spines