Vegetative key to the families

LEAVES REDUCED TO SCALES ON THE AERIAL STEMS
Saprophytic herbs (one a climber) usually without chlorophyll Orchidaceae
Plants epiphytic on trees, logs, rocks
Leaves linear, many times longer than broad
Leaves not basal, terete Dendrobium
Leaves long, terete succulent circular in cross section or ± flattened. Flowers not resupinate (i.e. labellum uppermost in flower)
Leaves obscurely corrugated, usually curved, 6–11 cm long. Rhizomes creeping on rocks. Stems branching, pendulous, 25–50 cm long. Flowers solitary or 2 together, 25–30 mm diam. Coast to Blue Mts On rocks. Fl. Sept.–Nov. Dendrobium striolatum
Leaves smooth, pendulous, 10–70 cm long. Stems up to 2 m long. Racemes lateral or from the bases of the leaves, many-flowered. Pencil Orchids