WHAT AN UPBEAT combination: longevity, energy, success and beautiful flowers--all of which embellished the prominence and affection that Zachariah D. Blackistone enjoyed in this capital city for who he was instead of simply for how long he had managed to be among us. To have lived to the age of 111 is still amazing, even in this day of regular 100th birthdays that Washington's own Willard Scott relays every morning on the "Today" show. Imagine: Mr. Blackistone breezed by his 100th birthday more than a decade ago--still marvelously busy as a working florist.

Mr. Blackistone was a regular presence at the main store seven days a week for most of the 84 years of the business he founded here--reporting in by 7:30 a.m. (except on Sundays, when he attended church at 8), after a round of calisthenics and maybe 200 yards of pacing in the hallways of his apartment. At the shop he was never content to sit back and play executive; there were flowers to tend, books to oversee and customers to chat with.

That's something more than "spry," the word that tends to recur in items about the elderly; Mr. Blackistone's keen interest in the community showed a delightful disrespect for his age--to the point that many Washingtonians began to believe those birthdays would just keep on happening. After all this time, it is an understatement, of course, to say that Mr. Blackistone will be missed in this town. But the countless pleasant moments he brought to so many will be remembered with lasting appreciation.