Produced by Marilynda Fraser-Cunliffe, Leonard Johnson and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images produced by Core Historical Literature in Agriculture (CHLA), Cornell University) THE GENUS PINUS PUBLICATIONS OF THE ARNOLD ARBORETUM No. 5 THE GENUS PINUS BY GEORGE RUSSELL SHAW [Illustration: Printer's Logo.] Es giebt jedoch auch Arten--und dieses ist für den Systematiker wie für den Physiologen gleich wichtig--welche sich den wechselnden Bedingungen der Feuchtigkeit so vollkommen anpassen, dass ihre extremen Formen zu ungleichen Arten zu gehören scheinen. _Schimper._ CAMBRIDGE PRINTED AT THE RIVERSIDE PRESS 1914 REPRINTED 1958 BY THE MURRAY PRINTING COMPANY FORGE VILLAGE, MASSACHUSETTS CONTENTS Page Plate PART 1 CHARACTERS OF THE GENUS 1 Cotyledon, Primary Leaf, Bud and Branchlet 1, 2 I Secondary Leaves 2 II External Characters 4 Internal Characters 4 Flowers and Conelet 7 III Cone 8 IV Phyllotaxis 12 V Cone-tissues and Seeds 12-16 VI Wood 17 VII Bark 18 PART 2 CLASSIFICATION OF THE SPECIES 22 Sections, subsections and groups 25 Section Haploxylon 26 Subsection Cembra 26 Group Cembrae 26 Pinus Koraiensis, Cembra, Albicaulis 26, 27 VIII Group Flexiles 28 Pinus Flexilis, Armandi 28, 30 IX Group Strobi 30 Pinus Ayacahuite, Lambertiana 30, 32 X Parviflora, Peuce, Excelsa 32, 34 XI Monticola, Strobus 34, 36 XII Subsection Paracembra 36 Group Cembroides 38