Rafflesia patma

The specific epithet is derived from patma, the Javanese vernacular name of the plant.[7] That name itself originates etymologically from the word पद्म (padma), Sanskrit for 'lotus'.[8]

The wider world of Western science was first introduced to the giant flowers of Rafflesia in a classic article by Robert Brown in the Transactions of the Linnean Society, published in 1821, but read before the Society in 1820, and distributed throughout Western Europe in pre-print.[5] In this reading and publication Brown introduced the name R. horsfieldii for a plant from Java.[9] No holotype exists, Brown never saw an actual plant: a drawing was made of the plant in Java by the American naturalist Thomas Horsfield which was sent to England, but this has been lost for a very long time.[5][10] Brown originally described a plant which had flowers 3 inches across. In his later publication on the genus Rafflesia,[10] published in 1840 (finally, a decade after the paper was read before the Society),[5] Brown changed the description to state that the radius was 3 inches, and the flower thus 6 inches across.[10]

The authors of the 1963 (English version of the) Flora of Java offered the theory that Brown had been confused with Rhizanthes zippelii, and proposed to synonymise the name Rafflesia horsfieldii with that taxon,[10][11] but this theory was later rejected by Willem Meijer in 1988, the Rafflesia expert at the time, on the basis of the flowers being too small, and because Brown described the plant as otherwise similar in form to R. arnoldii, with processus on the columna – while Rhizanthes quite obviously have many more perianth-lobes than the five of Rafflesia, making this unlikely to be overlooked by Brown. No Rhizanthes species is known with such relatively small flowers. There are a few Rafflesia species with flowers down to 5 inches across, but these occur in the Philippines, far from Java.[10]

In 1999, David Mabberley, writing a work on the place of Brown in the history of botany, stated that Meijer had "inexplicably" ignored the name during his work revising the taxonomy of the Rafflesiaceae in the 1990s. Mabberley was apparently himself ignorant of the preceding synonymy with Rhizanthes, and did not consult the relevant works, and as such synonymised the species with the largest flowers on Java, R. patma, with R. horsfieldii, with the simple explanation of "Brown's remarks".[5] In fact, Meijer had stated that on the basis Brown's remarks, and without the drawing, it may be impossible to ever know what Brown was referring to.[10] Nevertheless, as of October 2020, databases such as Plants of the World Online have indexed Mabberley's taxonomic interpretation,[2] although R. patma is accepted as the correct name for the extant taxon by other sources.[12]

In 1997 Meijer made the very rarely seen R. zollingeriana a synonym of R. patma,[3] but molecular studies published 2010 into the genetic variation of the genus found that R. zollingeriana was distinct.[12]

Rafflesia patma shares Java with two other species of Rafflesia: R. zollingeriana, the most common, and R. rochussenii. R. zollingeriana only occurs inland in the mountains of the southeast of the island, although R. patma does occur on or along the southern coasts. R. rochussenii is the only species on the island in which the tiny stalked warts (ramenta) on the inside surface of the perianth-tube are shaped somewhat like disc-like knobs on long stalks. In R. patma these warts are reduced or even somewhat absent, but in R. zollingeriana the tube is densely covered in ramenta ending in acute points, and some of the ramenta can be branched.[11] The pale colour of R. patma flowers is also a distinctive characteristic.[13]