Rhododendrons: Why these antiques of the plant kingdom must be conserved
There may be around 1,000 species of rhododendrons in the world but several are vulnerable due to habitat destruction.
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Observations on the Soil Acidity of Ericaceae and Associated Plants in the Middle Atlantic States
Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 72, No. 1 (Jan. - Apr., 1920), pp. 84-111 (28 pages) ...