Bug report

Bug summary

Setting

font.family: serif

Does not effect math text like ax.set_xlabel('$E / \mathrm{GeV}$').

Code for reproduction

import matplotlib.pyplot as plt

plt.rcParams['font.family'] = 'serif'
plt.plot([1, 2, 3])
plt.xlabel('$E / \mathrm{GeV}$')
plt.ylabel('E / GeV')

Actual outcome

sans-serif font for the axis label using math

Expected outcome

Both axes labels using serif font

Matplotlib version

• Operating System: Ubuntu 16.10
• Matplotlib Version: 2.0.2
• Python Version: 3.6