Question: Can Chasmanthe and Heracleum be distinguished as being of a different genus or family? 

Context paragraphs:
Heracleum (plant): Heracleum is a genus of about 60 species (depending on taxonomic interpretation) of biennial and perennial herbs in the carrot family Apiaceae.  They are found throughout the temperate northern hemisphere and in high mountains as far south as Ethiopia.  Common names for the genus or its species include hogweed and cow parsnip.

Sternarchogiton nattereri: Sternarchogiton nattereri is a species of weakly electric knifefish in the family Apteronotidae.  It is native to the Amazon River system and feeds on sponges. Unlike other members of the genus "Sternarchogiton", there is pronounced sexual dimorphism in "S. nattereri", with reproductively mature males developing strong external teeth on tips of their jaws.  These males are so different from the females and juveniles that they were thought to be a different genus and species, the "tooth-lip knifefish" "Oedemognathus exodon", for over 40 years.

Paranthodon: Paranthodon ( ) is a genus of extinct stegosaurian dinosaur that lived in South Africa during the Early Cretaceous, between 145.5 and 136.4 million years ago.  Discovered in 1845, it was one of the first stegosaurians found.  Its only remains, a partial skull and isolated teeth, were found in the Kirkwood Formation.  British paleontologist Richard Owen initially identified the fragments as those of the pareiasaur "Anthodon".  After remaining untouched for years in the British Museum of Natural History, the partial skull was identified by South African paleontologist Robert Broom as belonging to a different genus; he named the specimen "Palaeoscincus africanus".  Several years later, Hungarian paleontologist Franz Nopcsa, unaware of Broom's new name, similarly concluded that it represented a new taxon, and named it "Paranthodon owenii".  Since Nopcsa's species name was assigned after Broom's, and Broom did not assign a new genus, both names are now synonyms of the current binomial, "Paranthodon africanus".  The genus name combines the Ancient Greek "para" (near) with the genus name "Anthodon", to represent the initial referral of the remains.

Brachiosaurus nougaredi: "Brachiosaurus" nougaredi was a giant sauropod dinosaur of uncertain affinities.  It was originally assigned to the genus "Brachiosaurus" in 1960, though it certainly represents a different genus, and probably a different family.

Labulla: Labulla is a genus of linyphiid spiders with three species ranging from Western Europe to Russia, and a fourth species in India that may not be closely related to the other three, and may belong in a different genus.  Individuals range from 4.0 to in body length, with females being larger than males.  "Labulla" was erected in 1884 by the French naturalist Eugène Simon to encompass the species previously known as "Linyphia thoracica", and in the subsequent century over a dozen species were assigned to the genus, many of which have since been assigned to different genera.

Oreophysa: Oreophysa is a genus of flowering plants in the legume family, Fabaceae.  It belongs to the subfamily Faboideae.  The first species in this genus to be discovered, in 1843 by H. F. Jaubert & E. Spach, was initially mis-classified as belonging to a different genus.  However as it differed in suffruticose growth, and other characteristics so was later identified as belonging to a different species, to be named Oreophysa.

Istiodactylus: Istiodactylus is a genus of pterosaur that lived during the Early Cretaceous period, about 120 million years ago.  The first fossil was discovered on the Isle of Wight in England, and became the holotype specimen of a new species, "O. latidens" (Latin for "wide tooth"), in the genus "Ornithodesmus" in 1901.  This species was moved to its own genus, "Istiodactylus", in 2001; this name is Greek for "sail finger".  More specimens were described in 1913, and "Istiodactylus" was the only pterosaur known from three-dimensionally preserved fossils for much of the 20th century.  In 2006, a species from China, "I. sinensis", was assigned to "Istiodactylus", but it has since been found to belong to a different genus.

Anubias afzelii: Anubias afzelii is a species belonging to the Aroid genus "Anubias".  It was first described scientifically by Heinrich Wilhelm Schott in 1857, based on material collected in Sierra Leone by Adam Afzelius, after whom the species was named.  The genus "Anubias" was described simultaneously, with only "A. afzellii" belonging to it, which therefore is the type species of the genus.  No other species currently placed in the genus "Anubias" was described earlier (in a different genus) and "A. afzelii" was therefore the first species of this genus known to science.

Chasmanthe: Chasmanthe is a genus of flowering plants in the iris family, first described in 1932.

Echo (damselfly): Echo is a genus of damselflies belonging to the family Calopterygidae.  There are five species.  A sixth, "Echo maxima", is sometimes included, but it probably belongs to a different genus.

Supporting paragraphs: Chasmanthe Heracleum (plant)
Answer: yes