Herbarium Sheet · No. 0017

PPZZ.lu

Familia · Internetaceae  ·  Pressed MCMXXIV

An open botanical reader from the PPZZ Herbarium, Luxembourg. Begin by holding the leaf flat against the page. Read slowly; the lessons unfold without asking.

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Lesson 01

Etymology of PPZZ

Begin by treating the four letters as a dichotomous key. You will work from the first character downward, as one keys out a plant: at each step the page asks a yes-or-no question, and you follow the branch that matches your specimen.

Notice that the second P inverts to become a Z when the page is rotated. This is the hinge of the name: P over P, then Z over Z — a fold, then its mirror. Hold the sheet to the window if you need to see it.

Petals present? — yes Pistil count = 2? — yes Z-axis symmetry? P P Z — no Z
Figure 1. The PPZZ key, drawn as one keys out a Luxembourg field plant. Terracotta dots mark decision points.

What you should observe: four terminal letters, P · P · Z · Z, reached by following only the branches that fit. If your specimen has dried unevenly, that is correct.

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Lesson 02

The Luxembourg Flora Index

Five specimens were pressed for this folio, all gathered from the slopes above the Alzette. Lay each one flat and read the leader-lines into the margin. The terracotta strokes are the leaf; the faint sage strokes are the veins; the thin line that reaches outward terminates at a numbered tag.

a
Tilia · linden leafa — cordate base, asymmetric
b
Fagus · beech twigb — alternate, wavy margin
c
Sorbus · rowan clusterc — pomes in a corymb
d
Vicia · common vetchd — pinnate, tendril-tipped
e
Carduus · dried thistle heade — involucral bracts, spined

What you should observe: five sheets, five leader-lines, five tags. None of the leaves are symmetrical; pressed plants never are.

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Lesson 03

A Counter-Rotating Compass

This lesson contains a single instrument: a botanical compass rose, eight leaf-petals around a center. As you read downward, the petals turn the other way. Reading is motion, and the page returns the motion to you — a small mechanical courtesy.

Watch the petals, then watch the numeral tabs in the left margin. Both hold a kind of stillness against your scrolling, but they hold it differently: the petals spin, the digits merely refuse to rotate.

N E S W
Figure 2. The compass rose. Petals counter-rotate at a fraction of scroll velocity; the cardinal letters stay put.

What you should observe: downward reading turns the rose leftward. If you scroll back up, it returns. The motion is reversible, like a pressed leaf un-pressed.

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Lesson 04

Marginalia and Margin Pins

Every paragraph in this folio can carry a note. The notes live in the right gutter, written in a hand that is not the page's hand. Read the body first; let the marginalia arrive after, the way a teacher's pencil arrives after the printed line.

Press your thumb gently along the right edge. You will feel — or imagine you feel — the small brass tacks that pin each note to the sheet. They are decoration, but they are functional decoration: a tack means this note belongs here.

If a note seems to drift as you scroll, do not be alarmed. It is finding its level, like floating debris on still water. Wait, and it settles next to the line it annotates.

What you should observe: the body says one thing plainly; the margin says a second thing, sidewise. Both are correct. A folio is two voices kept close.

colophon