Weekly test crossword

When all the answers are in place, the letters in squares 14 to 21 and 25 to 30 will spell out a song title with an unusual horticultural link, while the name of the writer and singer will be found hidden in the top and bottom rows of the grid.

ACROSS

8 Theory associated with Charles Darwin (9) 9 European mountain range (4) 10 Margaret ___, English novelist (7) 12 Citrus fruit (6) 13 Also (3) 14 Wild cat of central and South America (6) 17 Olive genus (4) 18 Fruit of the genus Pyrus (4) 19 ___ the Roof, No 1 hit for Robson and Jerome in 1995 (2,2) 20 Simple card game (4) 21 Strong drink, or ghost? (6) 22 Plant seeds (3) 24 Part of a flower that receives pollen (6) 26 Shorten a book (7) 30 Midday (4) 31 Give a specified name to (9)

DOWN

1 Tall water grass (4) 2 Small Hebridean island (4) 3 Having no feeling (4) 4 Light sleeveless padded jacket (5) 5 Spectators, observers (9) 6 Molten rock (4) 7 Pasta, and type of squash (9) 11 Be quiet! (4,2) 15 Cultivated variety of Pink (9) 16 ‘Mother-of- ___’, common name of certain prolific creeping plants (9) 17 Italian noble family that produced five Popes (6) 23 Middle of the body (5) 25 Unit of heredity (4) 27 Capital of Latvia (4) 28 Expensive, or beloved (4) 29 Always (4)