If you need help with names, this is a great option. Not only does it include fantasy names, but also historical names and even species and weapon descriptions. It's lots of fun to play with, and I found quite a few good ideas for a demon series I'm going to be working on next.

http://fantasynamegenerators.com/

I didn't see any just straight "Nature" inspired names, so i decided to create my own. I may end up submitting them to the name generator site.

Girl-
Alyssa
Amber
Amethyst
Angelica
Apple
April
Aria
Aspen
Aurelia
Aurora
Autumn
Azalea
Beryl
Blossom
Brook
Brooke
Bryony
Cadence
Calla
Camellia
Carina
Cassa
Chandra
Cheyenne
Chrysanthe
Clementine
Clover
Coral
Crystal
Dahlia
Daisy
Danica
Danika
Daphne
Dawn
Delilah
Destiny
Diamond
Dove
Ebony
Eden
Electra
Elektra
Emerald
Eve
Faith
Fauna
Fawn
Fleur
Flora
Gaia
Gale
Garnet
Ginger
Hayley
Harmony
Haven
Hazel
Heather
Holly
Honey
Hyacinth
Iris
Ivory
Ivy
Jade
Jasmine
Jewel
Karma
Kailani
Kalei
Kalina
Kyla
Laleh
Lapis
Laurel
Lazuli
Lelani
Lavender
Lila
Lillian
Lily
Love
Luna
Marigold
Marin
Meadow
Melissa
Misty
Myrtle
Nova
Olivia
Opal
Pandora
Pearl
Pepper
Peridot
Petunia
Poppy
Primrose
Rosa
Rose
Rosemary
Rosetta
Ruby
Sable
Saffron
Sapphire
Savannah
Sharon
Sienna
Sierra
Silver
Skye
Stella
Summer
Sunny
Sunshine
Swann
Tansy
Teal
Tempest
Terra
Tierra
Topaz
Venus
Veronica
Violet
Willow
Windy
Winter
Wynter

Boy-
Aegis
Aedan
Aiden
Archer
Ash
Asher
Aspen
Austin
Axel
Badr
Bay
Barrow
Basil
Birch
Blaze
Blue
Bran
Brighton
Buck
Cade
Chase
Clay
Cliff
Clyde
Cobalt
Colt
Cypress
Dale
Dante
Delta
Drake
Dusty
Eban
Edan
Everest
Falcon
Flint
Ford
Forrest
Fox
Frost
Gideon
Glenn
Glyn
Grove
Hawk
Hawke
Heath
Hudson
Hunter
Huntley
Hyatt
Hyde
Jasper
Jericho
Jet
Jett
Kodiak
Kylan
Kyle
Leif
Leo
Leon
Lynx
Macon
Mai
Mansi
Marino
Mason
Onyx
Orion
Pembroke
Pike
Quest
Quill
Reed
Ridge
Rio
Roan
Rowan
Rue
Ryland
Shadow
Slate
Steele
Sterling
Stone
Talon
Thorn
Tiger
Wolf
Wolfe
Wren

Unisex-
Angel
Ari
Avis
Azure
Blair
Briar
Dakota
Ember
Fern
Indigo
Jordan
Laurel
Nova
Phoenix
Rain
Raine
Raven
River
Robin
Sage
Sol
Storm
Stormy

My generator is up! They added a bunch more too I think, so check it out if you need a nature-based name that is "real".

http://fantasynamegenerators.com/nature-names.php#.VohVWBFVikq