Helen Allen View Biography 225 Philodendron bipinnatifidum, Helen Allen 201713 Cobaea scandens, Helen Allen 2006Acca sellowiana Helen Allen 200768 Macleaya microcarpa, Helen Allen 200967 Aloe variegata, Helen Allen 200982 Fagus sylvatica 'Aspleniifolia', Helen Allen 2010105 Brahea armata, Helen Allen 2011112 Rosa x centifolia (syn Rosa gallica var. centifolia), Helen Allen 2012137 Rosa rubiginosa (syn R.eglanteria), Helen Allen 2013