Biform

Leaves binate, from 5 to 9 cm. long; resin-ducts medial, or with an occasional internal duct, hypoderm biform when of two rows of cells. ❋ George Russell Shaw (1892)

Leaves ternate, from 7 to 14 cm. long; resin-ducts medial, or with an occasional internal duct, hypoderm biform. ❋ George Russell Shaw (1892)

Leaves ternate or binate, from 10 to 15 cm. long; resin-ducts medial or with an occasional internal duct, hypoderm biform. ❋ George Russell Shaw (1892)

Leaves binate, from 4 to 8 cm. long; resin-ducts medial, or with an occasional internal duct; hypoderm biform. ❋ George Russell Shaw (1892)

Leaves ternate, from 8 to 16 cm. long; resin-ducts medial or with one or more internal ducts, hypoderm biform. ❋ George Russell Shaw (1892)

Leaves ternate, from 12 to 20 cm. long; resin-ducts medial or medial and internal, hypoderm biform. ❋ George Russell Shaw (1892)

Leaves in fascicles of 3, from 20 to 45 cm. long, rigid; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. ❋ George Russell Shaw (1892)

Leaves binate, from 2 to 4 cm. long; resin-ducts medial, hypoderm biform. ❋ George Russell Shaw (1892)

Leaves in fascicles of 2 to 5, from 15 to 22 cm. long; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. ❋ George Russell Shaw (1892)

All the species are of the Western Hemisphere, and among them may be found the biform hypoderm of the leaf, the internal resin-duct, and the total absence of external resin-ducts, characters common in ❋ George Russell Shaw (1892)

Leaves binate, from 3 to 5 cm. long; resin-ducts medial, hypoderm biform. ❋ George Russell Shaw (1892)

Among Hard Pines there is no Old World species with a biform hypoderm. ❋ George Russell Shaw (1892)

Leaves in fascicles of 2 and 3, or more in its southern range, from 12 to 25 cm. long; resin-ducts internal, hypoderm biform, endoderm with thin outer walls. ❋ George Russell Shaw (1892)

In most species, however, the epiderm is distinct, while the cells of the hypoderm are either uniform, with equally thin or thick walls -- or biform, with very thin walls in the outer row of cells and very thick walls in the inner row or rows of cells -- or multiform, with cell-walls gradually thicker toward the centre of the leaf. ❋ George Russell Shaw (1892)

The biform hypoderm is not always obvious (clausa, Banksiana, etc.) where in some leaves there is but one row of cells. ❋ George Russell Shaw (1892)

Leaves in fascicles of 3, 4 or 5, not exceeding 24 cm. in length; resin-ducts internal, often with one or two medial ducts, hypoderm biform, endoderm usually with thin outer walls. ❋ George Russell Shaw (1892)

Leaves in fascicles of 2, from 9 to 12 cm. long; resin-ducts medial, hypoderm weak, sometimes of a single row, biform when of two rows, endoderm with thin outer walls. ❋ George Russell Shaw (1892)

Leaves prevalently in fascicles of 3, but varying from 3 to 5, from 10 to 20 cm. long; resin-ducts medial, sometimes with an internal duct, hypoderm biform, endoderm with thick outer walls. ❋ George Russell Shaw (1892)

Leaves binate, from 10 to 15 cm. long; resin-ducts medial, hypoderm biform. ❋ George Russell Shaw (1892)

Since the death of St. Simon and Fourier, not one among their numerous disciples has attempted to give to the public a scientific demonstration of this grand maxim; and I would wager a hundred to one that no Fourierist even suspects that this biform aphorism is susceptible of two interpretations. ❋ Unknown (1890)