I like this word. Most useful, I would think, in describing something arranged in such an order. Even then, though, more of a curiosity than anything else.
abecedarian, a. and n.
1. Of or pertaining to the alphabet; marked with the alphabet; arranged in alphabetical order, as abecedarian psalms, like the 119th.
2. Occupied in learning the alphabet, or pertaining to one so occupied.
1. One occupied in learning the alphabet. In U.S. the regular school term.
2. One engaged in teaching the alphabet and merest rudiments of instruction.
There is also:
abecedary, a. and n.1
1. Of or according to the alphabet; alphabetic; marked with the alphabet; arranged in alphabetical order.
2. Engaged with or needing to learn the alphabet; illiterate.
B. n. An abecedary scholar or teacher. (Cf. Florio 1611, Abecedário, a teacher or learner of A B C.)