▁ 1 9 2 5 , ▁the ▁Al leg hen y ▁Mountains . ▁A ▁trip ▁in ▁ 1 9 2 6 ▁took ▁him ▁to ▁Minnesota , ▁Iowa , ▁Neb r aska , ▁Kansas , ▁and ▁the ▁Dak ot as . ▁His ▁final ▁field ▁expedition ▁was ▁in ▁ 1 9 2 9 ▁to ▁Kansas ▁and ▁Minnesota ▁but ▁it ▁was ▁cut ▁short ▁due ▁to ▁ill ness ▁and ▁only ▁included ▁work ▁in ▁Kansas . ▁ ▁He ▁was ▁a ▁pro l ific ▁research ▁publish er , ▁he ▁described ▁around ▁ 1 7 0 0 ▁new ▁species ▁in ▁the ▁course ▁of ▁his ▁career . ▁ ▁His ▁expert ise ▁was ▁princip ally ▁in ▁the ▁fl ora ▁of ▁the ▁Great ▁Pla ins ▁and ▁Rock y ▁Mountains . ▁From ▁ 1 8 9 9 , ▁R yd berg ▁was ▁on ▁the ▁staff ▁of ▁the ▁New ▁York ▁Botan ical ▁Garden , ▁and ▁he ▁later ▁became ▁the ▁first ▁cur ator ▁of ▁the ▁Garden ' s ▁Her b arium . ▁ ▁Dr . ▁R yd berg ▁was ▁elected ▁to ▁membership ▁in ▁the ▁Tor rey ▁Botan ical ▁Club ▁in ▁ 1 8 9 6 . ▁In ▁ 1 9 0 0 ▁he ▁joined ▁the ▁American ▁Association ▁for ▁the ▁Ad van cement ▁of ▁Science ▁and ▁was ▁elected ▁a ▁fellow ▁the ▁following ▁year . ▁Also ▁that ▁year , ▁he ▁was ▁chosen ▁as ▁an ▁Associ ate ▁of ▁the ▁Botan ical ▁Society ▁of ▁America . ▁In ▁ 1 9 0 7 ▁he ▁became ▁a ▁member ▁of ▁the ▁American ▁Ge ographical ▁Society ▁and ▁the ▁E colog ical ▁Society ▁of ▁America