Compact Hylleraas-type wavefunctions of three types, denoted A, B and C, are constructed for the S-2 ground states of the lithium atom and its isoelectronic ions Be+, B2+, . . . , Si11+. All the exponents and powers of the basis functions are optimized. The 20-term type B and 50-term type C wavefunctions are as accurate as several significantly larger expansions reported in the literature. The 50-term type C wavefunctions predict energies accurate to better than 3 parts in 10(7). (C) 2002 Elsevier Science B.V. All rights reserved.