Martelli is known for his studies of and contributions to the systematics of the tropical genus Pandanus and his taxonomic definition of the flora of Sardinia.

The holotype specimen was first described by Martelli in 1906 and is now preserved in the collections of the University of Florence in Italy.

[1][failed verification] His student Odoardo Beccari, used Martelli's herbarium for his own research on the definition of the monocot genus Pandanus.

In 1905 in Florence, Martelli founded the Webbia Journal of Plant Taxonomy and Geography.

Martelli named the journal in honor of Philip Barker Webb (1793–1854), a friend of Filippo Parlatore.

[2] The genus Martellidendron in the family Pandanaceae, previously recognized as a section of the genus Pandanus, was separated in 2003 on the basis of phylogenetic studies that used chloroplast DNA sequence data.

The genus was originally named by Rodolfo Emilio Giuseppe Pichi-Sermolli in Martelli's honour.

(1888) (now Dyschoriste nagchana (Nees) Bennet Hygrophila coerulea Martelli—Nuovo Giorn.