What's the difference between polyandria and polyandrous?

Polyandria

Definition:

(n. pl.) A Linnaean class of monoclinous or hermaphrodite plants, having many stamens, or any number above twenty, inserted in the receptacle.

Example Sentences:

Definition:

(a.) Belonging to the class Polyandria; having many stamens, or any number above twenty, inserted in the receptacle.

Example Sentences:

(1) A survey of 232 households of the Mosuo minority group in Yunnan Province, People's Republic of China, suggested that polyandrous matriarchy did not raise the birth rate per household, but lowered the community birth rate by restricting many women's chances of marrying.
(2) Red-necked phalaropes are nonterritorial and polyandrous.
(3) Those species with monogamous and polyandrous social structures have the lowest canine dimorphism, while those with dominance rank hierarchies of males have the most canine dimorphism.
(4) The results showed that the polyandrous matriarchy did not raise the birth rate per household, but lowered the community birth rate by restricting the chances of women marrying (28.4% not married) due to the scarcity of unattached men.
(5) The study hypothesis is that for Musuo women, matriarchy is associated with higher fertility than patriarchy, and polyandrous marriage is associated with higher fertility than is monogamous matriarchy or monogamous patriarchy.
(6) Both reproductive patterns, concealed estrus and continuous receptivity, are explicable in relation to either monogamous or polyandrous mating systems.
(7) The polyandrous spotted sandpiper (Actitis macularia) is a species characterized by female dominance over males and predominant male parental care.
(8) Females occasionally are polyandrous and no territories are defended.