Plant Morphology Hilltop Arboretum Lycoseris grandis Asteraceae GENERAL

Plant Morphology Hilltop Arboretum Lycoseris grandis Asteraceae

GENERAL ORGANIZATION OF A VASCULAR PLANT Shoot System leaves Root System

Shoot System Root System

TYPES OF ROOT SYSTEMS Tap Root Fibrous Root

TYPES OF ROOTS primary (seminal) secondary or lateral adventitious

ADVENTITIOUS ROOTS roots arising directly from the shoot rather than the radicle or primary root prop roots in corn roots from stem cuttings roots from rhizomes & stolons roots from vines

Epidendrum conopseum (Orchidaceae)

STEMS segmented appearance nodes internodes

BUDS meristem and subtending bud scales axillary (lateral) terminal

Leaf Development

SCARS mark or indentation on stem surface leaf terminal bud scale (ring)

bud scale scars leaf scars

PITH TYPES

PITH TYPES

PLANT HABIT general growth form of plant caulescent with apparent aerial stem nodes & internodes apparent

PLANT HABIT general growth form of plant caulescent with apparent aerial stem nodes & internodes apparent acaulescent without apparent aerial stem nodes & internodes not apparent

Moccasin flower – Cypripedium acaule Aiton

PLANT HABIT nature of aerial stems herbaceous woody

PLANT HABIT nature of aerial stems herbaceous primary tissues only not woody persist for only 1 season

PLANT HABIT nature of aerial stems herbaceous primary tissues only not woody persist for only 1 season Can be perennial or annual woody primary & secondary tissues persist for more than 1 season Perennial shrub (fruiticose) tree (arborescent)

Secondary Growth

HERB plant with non-woody aerial stem that dies at end of growing season annual biennial perennial

ATYPICAL STEMS stolon rhizome tuber bulb

STOLONS horizontal above-ground rooting at nodes

RHIZOME horizontal below-ground aerial growth at ends or nodes scale leaves and/or leaf scars

TUBER thickened, fleshy, below-ground bearing buds in axils of scale leaves

BULB short stem bearing fleshy leaves 1 apical meristem adventitious roots

DISTINGUISHING BETWEEN THORNS, SPINES, AND PRICKLES Thorns Modified stems Spines Modified leaves Prickles Projections from epidermal cells

Thorn Spine

PARTS OF TYPICAL FOLIAGE LEAF blade petiole stipules one or more parts may be absent

PHYLLOTAXY arrangement of leaves on stem

PHYLLOTAXY leaf arrangement alternate opposite basal rosette fascicled imbricate whorled equitant

Basal leaves

Equitant

BLADE DIVISION division of blade into distinct segments – leaflets simple compound palmate pinnate

TYPES OF COMPOUND LEAVES Pinnate leatlets arising in two rows along rachis Palmate leaflets all arising from petiole apex

COMPOUND LEAVES once twice thrice

Pinna pl. = pinnae (used especially in fern leaves)

DISTINGUISHING BETWEEN SIMPLE & COMPOUND LEAVES ?

DISTINGUISHING BETWEEN SIMPLE & COMPOUND LEAVES look for axillary bud leaves have leaflets lack

LEAF SHAPE general outline of blade regardless of lobes or indentations

BLADE SHAPE ovate lanceolate linear filiform oblong orbicular deltoid cordate elliptic deltate

PREFIX OBindicates shape reversed ovate – obovate lanceolate - oblanceolate

APEX morphological tip of blade acute acuminate obtuse

BASE morphological base of blade junction of blade & petiole cuneate cordate sagittate oblique

MARGIN edge of blade entire serrate dentate crenate parted pinnatifid ciliate lobed cleft

A Quick Reference Guide for Leaf Morphology

VENATION arrangement of veins in blade parallel-convergent pinnate palmate pinnipalmate dichotomous not apparent

INDUMENTATION (PUBESCENT) glabrous pubescent (indumented)

VESTITURE TYPES stellate hirsute hispid glandular ciliate tomentose glaucous

Questions?