How do you add a dependency between issues when the + values besides stories doesn't have the option

[Peter Browning]

Using JIRA 7.13, in Portfolio, I am trying to add a dependency between tasks.  The instruction I have are to hover over the task for the "+" Icon and you would select dependency, then click on the issue you want to link to, followed by saving your changes.

When I hover over the issue and click the "+" sign, only "story" and "sub-task" are options.

How do I enable this?  I'm trying to setup Portfolio for my team and show the use cases, one of which is ability to see program level dependencies to remove obstacles for each team.