Lauraceae
A.J.G.H. KOSTERMANS
Krukoff Botanist, Rijksherbarium, Leiden, Netherlands.
Trees or shrubs (sub-family Cassythaceae hemiparasitic twiners), ever-green and deciduous, usually with slime and oil cells. Leaf buds naked or with bud scales or perulate with many scales. Leaves spirally arranged, sub-opposite or sub-verticillate, exstipulate, penni- or tri- or tripli-nerved, margin entire. Inflorescences definite, panicles, racemes, spikes, umbels or heads; the umbels surrounded by large, persistent bracts. Flowers bisexual or dioecious, actinomorphic, 3- or 2-merous. Perianth usually of 2 whorls of usually equal, 3 or 2 tepals. Fertile stamens in whorls of 3 or 2, usually 9 or 12-18; anthers 2- or 4-celled, the cells opening by flaps; the third and inner whorls usually with a gland at each side of the filaments (sometimes all filaments with glands); anthers introrse, extrorse or latrorse; 4th whorl usually staminodal or none. Ovary usually superior, rarely perigynous, exceptionally inferior, 1-celled with 1 pendulous, anatropous ovule; style 1, stigma small or inconspicuous, peltate or capitellate, often trigonous. Fruit a 1-seeded berry with thin, fleshy mesocarp and a large seed, without endosperm. The perianth either completely deciduous or persistent or developed into a disc- or cup-like cupule or the perianth tube completely enveloping the fruit. Chromosome number: usually n=12.
A large family of 36 genera and about 2000 species, mostly tropical in all the continents. Represented in Pakistan by 4 genera and 8 species excluding the mediterranean species, Laurus nobilis Linn. which is cultivated in Lahore and Abbottabad.
Acknowledgement: We are grateful to the United States Department of Agriculture for financing this research under P.L. 480.
