Manihot dulcis vs casava

Manihot dulcis and casava both are nouns.

Word	Noun	Adjective	Verb	Adverb
Manihot dulcis	Yes	No	No	No
casava	Yes	No	No	No

As nouns, casava is a hypernym of Manihot dulcis; that is, casava is a word with a broader meaning than Manihot dulcis:

Manihot dulcis: South American plant with roots used as a vegetable and herbage used for stock feed
casava: any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch

Other hypernyms of Manihot dulcis include cassava.

Manihot dulcis (noun)	casava (noun)
South American plant with roots used as a vegetable and herbage used for stock feed	any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch