1	"Sporophylls and leaves similar in size"	2
1	"Sporophylls distinctly shorter than leaves"	6
2	"Leaf margins prominently toothed"	3
2	"Leaf margins entire or with few obscure teeth at apex"	4
3	"Epiphytic plants; leaves less than 5 mm long"	"Huperzia filiformis"
3	"Terrestrial plants; leaves greater than 8 mm long"	"Huperzia serrata"
4	"Plants terrestrial, erect or decumbent; leaves 4–9 mm long; proliferous buds usually present"	"Huperzia australiana"
4	"Plants epiphytic, pendulous; leaves more than 10 mm long, without buds"	5
5	"Leaves glaucous, c. 4 mm wide"	"Huperzia dalhousieana"
5	"Leaves pale green to yellow-green, not glaucous, 1–2 mm wide"	"Huperzia squarrosa"
6	"Transition from sterile to sporogenous zone abrupt; sporophylls all similar in size"	7
6	"Transition from sterile to sporogenous zone gradual; sporophylls variable in size, smallest towards apex"	10
7	"Leaves ovate, obtuse"	"Huperzia marsupiiformis"
7	"Leaves lanceolate, acute to attenuate"	8
8	"Terrestrial or lithophytic plants, rarely epiphytic; sporogenous zone 3.5–4.5 mm diam."	"Huperzia varia"
8	"Epiphytic plants, rarely terrestrial or lithophytic; sporogenous zone 1–2.5 mm diam."	9
9	"Leaves petiolate, not in defined rows"	"Huperzia phlegmaria"
9	"Leaves adnate to branch, decurrent, arranged in 4 rows"	"Huperzia phlegmarioides"
10	"Sporophylls spreading, loosely imbricate"	11
10	"Sporophylls appressed, tightly imbricate"	12
11	"Leaves in alternating whorls of 3, 2.5–5 mm wide"	"Huperzia lockyeri"
11	"Leaves spirally arranged, 1–3 mm wide"	"Huperzia varia"
12	"Terrestrial plants, rarely epiphytic; leaves at 60–90° to axis"	"Huperzia varia"
12	"Epiphytic plants; leaves at 30–45° to axis"	13
13	"Leaves thick, to 2 mm wide, strongly keeled, sporogenous zone not 4-sided"	"Huperzia carinata"
13	"Leaves thin, 3–4 mm wide, not strongly keeled, sporogenous zone 4-sided"	"Huperzia prolifera"