Prize-winning crossword

When all the answers are in place, the letters in the even-numbered squares will spell out three species or variety names that are in some way patriotic!

ACROSS

5 Support for an artist’s canvas (5) 8 Perennial commonly known as the ‘11 across thistle’ (8) 9 Fruit of the oak (5) 10 Younger son of 18 across (4) 11 Spherical representation of the Earth (5) 12 Part of the circumference of a circle (3) 15 Ginger genus (8) 18 First gardener? (4) 20 Restrain, keep in check (4) 21 Wind-blown mound beside a beach (4,4) 22 Affirmative reply (3) 27 Girl’s name, the French for flower (5) 28 18 across’s garden (4) 30 Association of workers (5) 31 Common name of the grey, spiny plant Eryngium maritimum (3,5) 32 Something that veronica does well? (5)

DOWN

1 Fungal disease, especially of apples and pears (4) 2 Long-barrelled firearm (5) 3 Large branch (5) 4 Process by which nutrients are transported around a plant (7) 5 Valuable, hardy, flowering shrub with handsome, leathery leaves (9) 6 ‘___-in-summer’, common name of Cerastium tomentosum (4) 7 Alternative name for heather (4) 10 Rock plant also known as rock cress (6) 13 Older son of 18 across (4) 14 Humorous term for the state of being asleep (4,2,3) 16 ‘___ Bunting’, award-winning variety of hosta (4) 17 Partially-dried grape (6) 19 Libocedrus decurrens, the ‘___ cedar’ (7) 23 Vicia faba, ‘___ beans’ (5) 24 Greek storyteller (5) 25 Crazy fruits? (4) 26 ‘Cloud ___’, variety of Panicum virgatum (4) 29 Proverbially slippery fishes (4)