Weekly prize crossword

When all the answers are in place, the letters in the even-numbered squares from 12 to 30 will spell out the common name of the plant spelled out by the letters in squares 1 to 7.

ACROSS

8 Nickname for a Parliamentarian soldier in the Civil War (9) 9 US state, capital Salt Lake City (4) 10 Thunbergia alata, ‘black-eyed ___’ (5) 11 Very uncommon thing (6) 12 Anglo-Welsh river (3) 14 Spider or fly, for example (6) 15 Continental currency (4) 16 Midday (4) 19 Cluster of grass attached at the base (4) 21 Colour of a plant described as ‘cyaneus’ (4) 23 Casual cotton trousers (6) 25 Not many (3) 27 Joseph ___, architect and gardener who worked at Chatsworth (6) 28 Be very good at (5) 29 Shaft sunk to obtain water (4) 30 Of a plant, taking in oxygen and releasing carbon dioxide (9)

DOWN

1 Archer’s missile (5) 2 Health worker (5) 3 Thomas Alva ___, prolific American inventor (6) 4 Follow a winding course, as a river (7) 5 Species or variety name meaning ‘fragrant’ (7) 6 Nourishing substances (9) 7 Christian festival (6) 13 River of Dorset and Somerset (3) 14 Of land, unable to sustain crops (9) 17 Natural features of the landscape (7) 18 Plant disorder (7) 20 Enemy (3) 22 Plant shoot at the apex of a stem (6) 24 Showy plant (6) 25 Free-swinging tool used to cut hedges, etc (5) 26 Find the heaviness of (5)