These papers may help you and solve your purpose

1.Phylogeny and biogeography of the eastern Asian–North American disjunct

wild-rice genus (Zizania L., Poaceae)

http://www.cls.zju.edu.cn/sub/fulab/contents/Inter%20download/%E4%B8%9C%E4%BA%9A%E5%8C%97%E7%BE%8E%E9%87%8E%E7%94%9F%E7%A8%BB.pdf

2.ORIGIN, BIOGEOGRAPHICAL MIGRATIONS AND DIVERSIFICATIONS OF TURFGRASSES

http://agbioresearch.msu.edu/pdf/SE-132%20Turfgrass-1-16-13.pdf

3.The Eastern Asian and Eastern and Western North American

Floristic Disjunction: Congruent Phylogenetic Patterns

in Seven Diverse Genera

http://cals.ncsu.edu/plantbiology/Faculty/xiang/Xianglab/www/Papers/XiangSoltis1998b.pdf

4.DISPERSAL-VICARIANCE ANALYSES OF INTERCONTINENTAL DISJUNCTS:

HISTORICAL BIOGEOGRAPHICAL IMPLICATIONS FOR ANGIOSPERMS IN THE NORTHERN HEMISPHERE

http://www4.ncsu.edu/~qyxiang/Papers/XiangSoltis2001.pdf

5.Modelling chestnut biogeography for American chestnut restoration

http://192.38.112.111/pdf-reprints/Fei_DaD_2012.pdf

These papers are freely available on net.

Have a good day

My suggestion: Search for papers about 'Beringia' / 'Beringia land bridge' as the usual migration route between Asia and N-America:

http://scholar.google.de/scholar?q=beringia+fauna+migration&btnG=&hl=de&as_sdt=0

Thank you Tamal ans Michael these links were very helpful