THE BOTANICAL REVIEW VOL. 64 JULY-SEPTEMBER 1998 No. 3 The Tapetum and Systematics in Monocotyledons CAROL A. FURNESS AND PAULA J. RUDALL Royal Botanic Gardens, Kew Richmond, Surrey, TW9 3AE, U.K. I. Abstract ............................................................. 201 If. Introduction .......................................................... 202 Ill. Material and Methods .................................................. 202 A. Material ......................................................... 202 I. Species Examined with LM and TEM ............................... 203 2. Species Examined with LM Only ................................... 203 B. Methods ......................................................... 203 IV. Results .............................................................. 204 A. Secretory T a p e m m ................................................. 204 B. Plasmodial Tapetum ................................................ 204 C. Invasive Tapetum .................................................. 205 V. Discussion ........................................................... 205 A. General Systematic Discussion ....................................... 205 I. Orbicules ...................................................... 206 B. Commelinanar .................................................... 206 I. Palms and Possible Relatives ...................................... 206 2. Poales and Possible Relatives ...................................... 206 3. Commelinales .................................................. 207 4. Philydrales ..................................................... 207 5. Zingiberales .................................................... 207 C. Lilianac .......................................................... 208 Acknowledgments .................................................... 208 Literature Cited ....................................................... 209 VI. VII. I. Abstract This paper critically reviews the homologies and distribution oftapetum types in mono- cotyledons, in relation to their systematics. Two main types of tapetum are widely recog- Copies of this issue [64(3)] may be purchased from the NYBG Press, The New York Botanical Garden, Bronx, NY 10458-5125 USA. Please inquire as to prices. The Botanical Review 64(3): 201-239, July-September 1998 O 1998 The New York Botanical Garden 201