This section is from the book "Culinary Herbs", by M. G. Kains. Also available from Amazon: Culinary Herbs, Their Cultivation, Harvesting, Curing and Uses.
Finocchio, or Florence fennel (F. dulce, D. C), deserves special mention here. It appears to be a native of Italy, a distinct dwarf annual, very thickset herb. The stem joints are so close together and their bases so swelled as to suggest malformation. Even when full grown and producing seed, the plant rarely exceeds 2 feet. The large, finely cut, light green leaves are borne on very broad, pale green or almost whitish stalks, which overlap at their bases, somewhat like celery, but much more swelled at edible maturity, to form a sort of head or irregular ball, the "apple," as it is called, sometimes as large as a man's fist. The seeds are a peculiar oblong, much broader than long, convex on one side and flat on the other, with five conspicuous ribs.
Cultivation is much the same as for common fennel, though owing to the dwarf nature of the plant the rows and the plants may be closer together. The seedlings should be 5 or 6 inches asunder. They are very thirsty things and require water frequently.
When the "apple" attains the size of an egg, earth may be drawn up slightly to the base, which may be about half covered; cutting may begin about 10 days later. Florence fennel is generally boiled and served with either a butter or a cream dressing. It suggests celery in flavor, but is sweeter and is even more pleasingly fragrant. In Italy it is one of the commonest and most popular of vegetables. In other European countries it is also well known, but in America its cultivation is almost confined to Italian gardens or to such as supply Italian demands in the large cities. In New York it is commonly sold by greengrocers and pushcart men in the Italian sections.