1911] Bartlett,— Euphorbia arundalana 165 
2 dm. attingentes, deorsum alternatim, sursum dichotome vel tricho- 
tome ramosi. Folia inferiora squamiformia alterna, superiora 
verticillata vel saepius opposita, summis exceptis quam internodia 
multum breviora, amplitudine formaque valde varia, lanceolata vel 
ovata, mediocria circa 2 cm. longa, sessilia vel brevissime petiolata. 
Pedunculi erecti in dichotomiis (aut trichotomiis) terminales, quique 
involucrum unum ferentes, infimi usque ad 7 cm. longi internodia 
aequantes, summi foliis breviores. Involucrum  hemisphaerieum 
glandulis appendice lata patenti conspicua circumdatis. 
forma a omnino glabra, foliis caulibusque viridibus; involucri 
glandulis albo-appendiculatis. 
forma B omnino glabra, foliis caulibusque purpureis; involucri glan- 
dulis roseo-appendiculatis. 
forma y caulibus, praecipue nodis, foliisque pilosis deinde glabratis, 
purpureis; pedunculis glabris, involucris extus circulatim ad seg- 
mentorum baseis pubescentibus, alibi glabris; glandulis albo-appen- 
diculatis. 
In fine sand, southeast of Laurel, Maryland, in Anne Arundel 
County, 1 May, 1910, Bartlett 1954 (form a), 1955 (f. 6), and 1956 
(f. y). The three forms which are defined illustrate the types of 
variation shown by this species. Other forms are represented by 
Bartlett 1952 and 1953; many more might have been collected. 
Since the soil in which Euphorbia arundelana grows is agriculturally 
the best in the region, its native flora is but poorly preserved. The 
Euphorbias occur in fence corners and in the narrow strips of undis- 
turbed sand between roads and farm fences. 
Bureau or PLaNT IxpusrRY, Washington, D. C. 
