Chalicea

Nine characters who shared a location appear as the unclued lights (one of two words, one of three). Solvers must shade the surname of the person who wrote about them (five letters). Across 4 Mistakenly re-applied to group of fliers (11) 11    Tall palms occasionally covered by quotes for extinct plants (9) 13    Sadly ageing Hon.

The unclued lights are a small fraction of almost 800. Across 12   Oilmen rail about petroleum product (7,3) 13   Came across religious instruction chapter consisting of verses (6) 14   Bleat including angry tirade for this plant? (7) 15   Tea urns of Salvation Army medic, very apt resources, say, for starters (8) 19   Et voilà!