  We present measurements of the total production rates and momentum
distributions of the charmed baryon $\Lambda_c^+$ in $e^+e^- \to$ hadrons at a
center-of-mass energy of 10.54 GeV and in $\Upsilon(4S)$ decays. In hadronic
events at 10.54 GeV, charmed hadrons are almost exclusively leading particles
in $e^+e^- \to c\bar{c}$ events, allowing direct studies of $c$-quark
fragmentation. We measure a momentum distribution for $\Lambda_c^+$ baryons
that differs significantly from those measured previously for charmed mesons.
Comparing with a number of models, we find none that can describe the
distribution completely. We measure an average scaled momentum of $\left< x_p
\right> = 0.574\pm$0.009 and a total rate of $N_{\Lambda c}^{q\bar{q}} =
0.057\pm$0.002(exp.)$\pm$0.015(BF) $\Lambda_c^+$ per hadronic event, where the
experimental error is much smaller than that due to the branching fraction into
the reconstructed decay mode, $pK^-\pi^+$. In $\Upsilon (4S)$ decays we measure
a total rate of $N_{\Lambda c}^{\Upsilon} = 0.091\pm$0.006(exp.)$\pm$0.024(BF)
per $\Upsilon(4S)$ decay, and find a much softer momentum distribution than
expected from B decays into a $\Lambda_c^+$ plus an antinucleon and one to
three pions.
