Classification of organisms
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- GLOSSARY OF TERMS PERTAINING TO SHELLS
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- Pinus sp. PINE
A B 
C D Figure 8.1 A and B, external anatomy of bivalve shells, lateral view. C and D, external anatomy of gastropod shells, ventral view. GLOSSARY OF TERMS PERTAINING TO SHELLS (refer to Figure 8.1) aperture - the entrance or opening of the shell apex - the tip of the spire in snail shells body whorl - the last whorl of a snail shell; the one closest to the aperture canal - a narrow prolongation of the lip of the aperture containing the siphons in some snails columella - the pillar around which the whorls form their spiral circuit fluted - with a regular pattern of ridges and depressions running in the same direction as the radiating ridges from the umbo to the edge of the shell growth lines - lines on the surface of a shell indicating rest periods during growth hinge - where the valves of a bivalve are joined lips - the margins or edges of the aperture margin - the edges of the shell parietal wall - the inner lip area radiating - pertaining to ribs or lines that start at the umbo and extend fanwise to the margins siphon - the organ through which water enters or leaves the body of a clam siphonal canal - the groove or channel on one side of the aperture of a shell of a gastropod to accommodate the siphon spire - the upper whorls, from the apex to the body whorl suture - the spiral line of the spire, where one whorl touches another teeth - the pointed protuberances at the hinge of a bivalve shell; in snails, the tooth-like structures in the aperture. umbilicus - a small hollow at the base of the shell in snails umbo - the prominent part of a bivalve shell above the hinge valve - one part of a bivalve shell whorl - the distinct turns of a spire wing - a somewhat triangular projection of the shell of a bivalve - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - KEY TO THE CONIFER BRANCHES - GENERA Trees and shrubs; all our conifers belong here. Juniper is a low or prostrate shrub with green to blue berry-like structures instead of the typical cones. 1.a. Leaves needle-like, not concealing the twig ...................................................go to 2 1.b. Leaves scale-like, concealing the twig............................................................go to 6 2.a. Some of the leaves (needles) are in clusters ............................................go to 3 2.b. Leaves (needles) are solitary, none are in clusters ..................................go to 4 3.a. All leaves (needles) are clustered in 2’s or 5’s (Fig. 8.2, H,I)...........Pinus sp. go to pine species key 3.b. Leaves (needles) soft, both single and clustered, many in each cluster, clusters spirally arranged on twig; deciduous (Fig. 8.2, G)...........Larix laricina (Du Roi) Koch (tamarack, larch, hackmatack) 4.a. Leaves (needles) flattish in cross section, stalkless, leaving a smooth circular scar on the twig; twigs are smooth (Fig. 8.2,B).............................Abies balsamea (L.) Mill (balsam fir) 4.b. Leaves (needles) stalked,leaving a raised scar on the twig; twigs are not smooth (Fig. 8.2,C,D) ............................................go to 5 5.a. Leaves (needles) two-sided, flat .................................................Tsuga canadensis (L.) Carr (hemlock) 5.b. Leaves (needles) four-sided, square .....................................................Picea sp. go to spruce species key 6.a. Leaf covered twigs flat, fruit is a small, tan cone (Fig. 8.2, E).........Thuja occidentalis L. (white cedar) 6.b. Leaf covered twigs rounded, fruit blue, berry-like (Fig. 8.2, F)....Juniperus communis L. (common juniper) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - KEYS TO THE SPRUCE AND PINE SPECIES Picea sp. SPRUCE 1.a. Twigs not hairy, yellow-gray in colour; leaves (needles) blue-green, sharp; inner bark silvery-white..............................Picea glauca (Moench) Voss (white, pasture or cat spruce) 1.b. Twigs covered with fine, dense hair; leaves (needles) blunter, not sharp...................go to 2 2.a. Leaves (needles) yellowish-green, not shiny, rather long and blunt; bark orange-brown in colour; inner bark pale olive-green............................Picea rubens Sarg. (red spruce) 2.b. Leaves (needles) grayish or bluish-green; branches stiff; bark usually dark, inner bark deep olive-green................................Picea marina (Mill.) BSP (black or bog spruce) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Pinus sp. PINE 1.a. Leaves (needles) five in each bundle. (Fig. 8.2, H) .....................Pinus strobus L. (white pine) 1.b. Leaves (needles) two in each bundle (Fig. 8.2,I)..........................................................go to 2 2.a. Leaves (needles) 9 - 16 cm long, stiff; bark reddish ..........Pinus resinosa Ait. (red pine) 2.b. Leaves (needles) less than 8 cm long; bark not reddish ........................................go to 3 3.a. Leaves 4 - 6 cm long, not widely divergent; bark of upper branches and trunk yellowish ..............................................................Pinus sylvestris L. (scotch pine) 3.b. Leaves 1 - 4 cm long, widely divergent; bark of upper branches and trunk dark .......................................................................Pinus banksiana Lamb. (jack pine) 
Figure 8.2 A. Abies sp. (fir) twig (x0.5) B. Abies sp. twig & leaf showing leaf scars (x2) C. Tsuga sp. (hemlock) twig (x0.5) D. Picea sp. (spruce) twig & leaf showing scars (x2) E. Thuja sp. (cedar twig) (x0.5) F. Juniperus sp. twig (x0.5) G. Larix sp. (tamarack) twig (x0.5) H. Pinus strobus leaves (x).5) I. Pinus sp. (pine) leaves (0.5) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Download 431.98 Kb. Share with your friends:
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