These two groups are multicellular eukaryotes (cells
with membrane-bound nucleus and organelles) that produce their own food
by photosynthesis. Most are terrestrial but some plants have returned secondarily
to water during their evolution.
Stems and leaves are generally coated with a waxy cuticle that helps
prevent loss of water. Carbon dioxide and oxygen diffuse in and out of
the plants through microscopic pores in the leaf surface. Photosynthesis
takes place in cells organelles called chloroplasts containing green chlorophyll
and a variety of yellow,red and orange plant pigments.
Plant cells have walls made primarily of cellulose. Carbohydrate is
stored in the form of starch, generally in chloroplasts and other cell
organelles.
Adaptations
To obtain water and minerals from the soil, while also absorbing light
and taking in carbon dioxide, these plants have both an underground root
system and an above ground shoot system. Neither system can live without
the other. Lacking chloroplasts and living in the dark, roots would starve
without nutrients imported from the leaves of the shoot system. Conversely,
leaves and stems depend on the water and minerals absorbed by roots. A
system of tubes transport materials between shoots and roots.
Classification
Vascular plants are divided into those without seeds, mostly ferns and
some mosses; and those with seeds, mostly flowering plants and cone bearing
trees. Of the two groups of seed plants, gymnosperms (conebearers with
naked seeds) appear much earlier in the fossil record. They lack the enclosed
chambers in which angiosperm seeds develop.
Ferns (Division Pterophyta)
The earliest vascular plants were seedless and the ferns belong to one
of the four living divisions of plants that have retained this early condition.
Of all seedless vascular plants, ferns are the most extensively represented
in the modern flora. Ferns disperse via spores, rather than seeds. Unlike
seeds, each spore has half the complement of genetic material. Sexual
reproduction occurs later in the life cycle.
The leaves, or fronds, of ferns are compound, meaning each leaf is composed
of several leaflets called pinnae. The frond grows as its coiled tip,
the fiddlehead, unfurls. The leaves usually sprout directly from a horizontal
underground stem called a rhizome such as they do in brackens and sword
ferns.
Large tropical tree ferns, by contrast, have upright stems many meters
tall. The leafy fern plant familiar to us is part of the life cycle called
the sporophyte generation. The gametophyte stage is usually very small.
With their swimming sperm and fragile gametophytes, the majority of ferns
live in relatively damp habitats. The
Hairy Water-clover (Marsilea vestita) and the Mosquito
Fern (Azolla mexicana) are two rare aquatic ferns that
live in the dry southern interior of British Columbia.
Flowering Plants (Division Magnoliophyta)
Flowering plants, or angiosperms, are split into two classes: monocots
(Liliopsida), which have one embryonic seed leaf, and dicots (Magnoliopsida),
which have two seed leaves. Monocots and dicots also have several other
structural differences including the arrangement of major veins in their
leaves.
Many angiosperms require insects or other animals as dispensers to transfer
pollen from male to female sex organs. This makes pollination less random
than the wind-dependent pollination of gymnosperms.
Dicots - Peas, Buttercups, Sunflowers, Oaks and Maples
Among the many dicot families are roses, peas, buttercups, sunflowers,
oaks and maples. Many dicots have a taproot system, consisting of one
large, vertical root (the taproot) that gives rise to many smaller lateral
roots. Penetrating deep into the soil, the taproot provides a firm anchor.
Some taproots, such as carrots, turnips, sugar beets, and sweet potatoes,
are modified roots that store larger amounts of food. The plant draws
on these food reserves when it flowers and produces fruit. Dicots generally
have a multi-branched network of major veins in their leaves and floral
parts in multiples of four or five. There are many dicot plant species
that are endangered, threatened or rare in the dry southern interior of
British Columbia including:
Nettle-leaved Giant-hyssop (Agastache
urticifolia)
Dalles Milk-vetch (Astragalus
sclerocarpus)
Narrow-leaved Brickellia (Brickellia
oblongifolia)
Yellowish Paintbrush (Castilleja
lutescens)
Atkinson's Coreopsis (Coreopsis
atkinsoniana)
Whited's Halimolobos (Halimolobos
whitedii)
Showy Phlox (Phlox speciosa)
Munroe's Globe-mallow (Sphaeralcea
munroana)
Monocots - Grasses, Orchids, Palms, Lilies, and Yuccas
Monocots include: grasses such as wheat, corn, bamboos, and rice; orchids,
palms, lilies, and yuccas.
They generally have fibrous root systems consisting of a mat of threadlike
roots that spread out below the surface rather than a taproot.
Most monocots have parallel major veins that run the length of the leaf
blade and floral parts usually in multiples of three. Examples of endangered,
threatened and rare species of monocots in the Okanagan and Similkameen
valleys of southern British Columbia include:
Lyall's Mariposa Lily (Calochortus
lyalli)
Porcupine-grass (Stipa spartea)
Endangered Species
The species listed above are a few of the many endangered, threatened
and vulnerable species of plants living in the Okanagan and Similkameen
valleys of southern British Columbia. Due to loss of suitable habitat,
some of these species may become extinct without protection.
Grasslands, dominated by bunchgrasses and shrubs are the primary habitat
of concern in the dry, southern interior region of the province.
The ecosystem is poorly known, unlike the high public profile of
an old-growth forest, and yet is one of the most threatened natural
habitats left in Canada.
this section sponsored
by: 
Industry Canada
