United States

Aconite

Aconitum napellus

Critically Endangered

Admiralty Island Meadow Vole (Admiraltiae)

Microtus pennsylvanicus

Agrimony

Agrimonia eupatoria

Near Threatened

Ajuga

Ajuga reptans

Endangered

Alder

Alnus glutinosa

Alder leaf beetle

Agelastica alni

Alder Spittlebug

Aphrophora alni

All Species in United States

speckled rustwort

Marsupella sphacelata

Speckled Tar Spot

Rhytisma punctatum

Spence's feather-winged beetle

Ptiliolum spencei

Sphaeropsis blight

Sphaeropsis sapinea

Sphagnum Brownie

Hypholoma elongatum

Sphagnum Greyling

Sphagnurus paluster

Sphagnum Sprite

Nehalennia gracilis

Sphecid wasp

Ectemnius cephalotes

Spider

Coleosoma floridanum

Spider

Trochosa ruricola

Spider

Urozelotes rusticus

Spider beetle

Gibbium psylloides

Spider brake

Pteris multifida

Spider plant

Chlorophytum comosum

Spider wasp

Auplopus carbonarius

Spider Wasp

Ceropales maculata

Spiderwisp

Gynandropsis gynandra

Spiderwort

Tradescantia virginiana

Spidery Mossear

Rimbachia arachnoidea

Spike

Eurynia dilatata

spike awlsnail

Allopeas clavulinum

Spiked bur grass

Tragus berteronianus

Spiked pepper

Piper aduncum

Spiked Shieldbug

Picromerus bidens

Spiked speedwell

Veronica spicata

spiked water-milfoil

Myriophyllum spicatum

Spiked Wood-Rush

Luzula spicata

spinach

Eulithis mellinata

Spinach

Spinacia oleracea

Spindle Ermine

Yponomeuta cagnagellus

Spindle Shank

Gymnopus fusipes

Near Threatened

Spine-crowned Clubtail

Hylogomphus abbreviatus

Spined Soldier Bug

Podisus maculiventris

Spinose Thyme-Moss

Mnium spinosum

Spiny Baskettail

Epitheca spinigera

Spiny Cocklebur

Xanthium spinosum

Spiny fiddlewood

Citharexylum spinosum

Spinyfruit buttercup

Ranunculus muricatus

Spiny Gray Horsehair Lichen

Bryoria nadvornikiana

Near Threatened

spiny hands

Charybdis hellerii

Spiny Heath Lichen

Cetraria aculeata

Spiny holdback

Tara spinosa

Spiny naiad

Najas marina

Endangered

Spiny Pill Beetle

Chaetophora spinosa

Spiny restharrow

Ononis spinosa

Endangered

Spiny sowthistle

Sonchus asper

Spiny spiderflower

Tarenaya spinosa

spiral extinguisher moss

Encalypta procera

Spiral Extinguisher-Moss

Encalypta streptocarpa

spiral ginger

Costus pulverulentus

Spiral head ginger

Costus scaber

Spiral Tarcrust

Eutypa spinosa

spirea aphid

Aphis spiraecola

Spiritweed

Eryngium foetidum

Spitting spider

Scytodes univittata

Spitting Spider

Scytodes thoracica

Splachnobryum moss

Splachnobryum obtusum

Split Fibrecap

Pseudosperma rimosum

Splitlip hempnettle

Galeopsis bifida

Splitpea Shanklet

Collybia cookei