The triborate and pentaborate compounds 3-hydroxy-2,2-dimethylpropylammonium triborate(1+), [HOCH2C(CH3)(2)NH3][B3O3(OH)(4)] (1), and 2-hydroxyethylammonium pentaborate(1-), [HOCH2CH2NH3][B5O6(OH)(4)] center dot H2O (2), were prepared by crystallization from concentrated aqueous boric acid solutions containing the respective alcoholamines at a boric acid-alcoholamine mole ratio of 3.33:1.00. Compound 1 crystallized in the triclinic space group P (1) over bar with a = 5.9595(g) angstrom, b = 6.3024(g) angstrom, c = 15.594(2) angstrom, alpha = 91.218(2)degrees, beta = 91.138(2)degrees, gamma = 118.034(2)degrees, V = 516.56(13) angstrom(3), and Z 2; 2 crystallized in the monoclinic space group P2(1)/n with a = 11.2469(8) angstrom, b = 9.5091(6) angstrom, c = 11.5422(8) angstrom, beta= 90.175(1)degrees, V = 1234.41(15) angstrom(3), and Z = 4. Compound 1 contains a rare example of a structurally characterized hydroxyl-hydrated triborate monoanion. Comparisons are made with other known examples of this anion.