70 IOWA ACADEMY OF SCIENCE 
581. Euphorbia serpyllifolia Pers. Thyme-leaved Spurge. In sandy 
fields. 
582. Euphorbia glyptosperma Engelm. Ridge Seeded Spurge. Rare; 
Elmira. 
583. Euphorbia preslii Guss. Upright Spotted Spurge. A common 
weed of sandy soils. 
584. Euphorbia hirsuta (Torr) AVeig. Hairy Spurge. With the above. 
585. Euphorbia maculata L. Milk Purslane. Not uncommon in fields 
and gardens. 
586. Euphorbia hexagona Nutt. Angled Spurge. Rare within our 
borders ; Fremont Twp. 
587. Euphorbia margiuata Pursh. Snow-on-the-Mountain. Common as 
a wayside weed in dry places. 
588. Euphorbia corollata L. Flowering Spurge. Abundant in open 
places. 
589. Euphorbia dent at a Michx. Toothed Spurge. Not scarce in sandy 
soil. 
590. Euphorbia heterophylla L. Various-leaved Spurge or Fiddle 
Spurge. Common in woods, especially those of hilly clay soils. 
591. Euphorbia obtusata Pursh. Blunt-leaved Spurge. Not common, 
in damp woods. 
ANACARMACEAE. 
RHUS L. 
592. Rhus glabra L. Smooth Sumach. Common in dry soils. 
593. Rhus toxicodendron L. Poison Ivy or Poison Oak. Common in 
woodlands. 
594. Rhus toxicodendron Var. radicans (L.) Torr. With the above. 
CELASTRACEAE. 
EVONYMUS (Tourn) L. 
595. Evonynms atropurpureus Jaeq. Burning Bush or Wahoo. Rare 
in rocky wooded places. 
