In 2006 I worked up at Garden in the Woods, the native plant botanical garden and headquarters of the New England Wild Flower Society. While up there I met Erin Backus, entomologist and horticultural therapist from upstate New York, and we became quick friends. We had a fabulous time interning with the Horticulture Department adding our abilities and able hands to the garden. While I worked on various woody plant renovation and restoration projects Erin was busy fostering the populations of native moths and butterflies. With great signage and information accompanying her netted displays of different caterpillars feeding and metamorphosizing throughout the garden you quickly fell in love with these "fat cats" as she liked to call them. It was such fabulous work because it is very important for people who want to have beautiful butterfly gardens to know that you have to have both the flowers that the mature butterflies love, but also the plants that the larvae caterpillars need to feed on in order to grow and develop. Sometimes they are woody trees or shrubs, or sometimes much more tender perennials. Most larvae, especially moths and butterflies in the order Lepidoptera, are very specific as to what "host plant" or plants they feed on.
Enter the fennel and the fat cats I found today in the Conservatory Garden in Central Park.
Fennel we love for it's use as a vegetable and herb, with both culinary and medicinal uses. Botanically fennel is known as Foeniculum vulgare, a member of the family Apiaceae. Originally from the Mediterranean region of Europe fennel has now naturalized throughout North America. Hardy in Zones 5-10 Foeniculum has strong hollow stems and fine, wispy foliage upon which form these fun umbels (an inflorescence of flowers that makes a flat-top) of yellow flowers in summer. (I shot these in midday sun so you can't see the fine, soft foliage so well, sorry.)
Florence fennel is grown for it's big bulbous base, but there are also other, narrower varieties of fennel known as 'bronze' fennel, and this is the latter. It doesn't produce that fat base, at least not so far as I have seen, but it does produce the same aromatic stems and foliage that smell of anise. The plant provides a wonderfully soft backdrop and shot of yellow to the other more bold, showy annual plants that Curator Diane Schaub loves to play with in her yearly displays.
And in this case we learn that fennel is a great host plant if you want to have the eastern black swallowtail butterfly in your garden.
This is the late instar caterpillar, the larvae of a stunning native butterfly called the eastern black swallowtail, Papilio polyxenes. The day I captured these guys in the garden I saw some tiger swallowtails but no black swallowtails so I am still searching for a photo for you for reference. For now here is the wikipedia link.