Only a few to get.
66d Let up in arranging say for absence of central cylinder(6) ??t?l?
21a Having a handle Santa wound up sledge at the rear (6) a?s?t?
32a Virtuous grow old oddly (4) ?o?d
The only answer I can get from that it astely - rearrange say with let up - a stele is cylinder ina plant and "a" often means without. However, I cannot find such a word in my (admittedly limited!) dictionaries or on line! Happy hunting