The Department of Biology Greenhouse is holding its 28th annual spring plant sale on Tuesdays and Thursdays from noon until 6 p.m. through May 15 or until sold out.  The greenhouse is located at 333 Dale Street off State Farm Road near the Greenway Trail and intramural fields. Plant selections will include annuals, perennials and tropical foliage of all sizes. Plant care information will also be available. For more information, call 262-4025.