**2. Amaryllidaceae Crops—Botanical Characteristics and Biochemical Composition**

According to the current taxonomy, the family Amaryllidaceae consists of three subfamilies, Agapanthoideae, Allioideae, and Amaryllidoideae, comprised of about 80 genera and approximately 2200 accepted species [25]. Amaryllidaceae are perennial or biennial geophytes or hemicryptophytes, with very diversified morphology of their underground shoots, which let distinguish three biomorphological groups: rhizomatous, bulbous, and domesticated onions [26]. In the case of a rhizomatous group (*Cryptostephanus* spp., *Clivia* spp., and some *Scadoxus* spp.), fleshy rhizomes act as storage organs, growing for several years through the successive development of the basal plate. Bulbs, composed of leaf sheaths of varying thicknesses, are formed by rhizomes. The leaves are evergreen. In the bulb group, the true bulb consists of a longitudinally compressed basal stem and fleshy, succulent, storage leaf bases. This group is well-adapted to arid and semiarid climate. Domesticated onions form storage bulbs and were grouped separately because of the diversified morphology, shaped through many centuries of breeding [26]. Most of the Amaryllidaceae plants prefer xerophytic ecosystems, with warm, dry summers and cool, wet winters, being distributed across regions, which are well-recognized biodiversity hotspots. The major center of genetic diversity is localized in Central Asia and Mediterranean basin, and the secondary one, in South Africa, western North America, and the Andes [27]. The gene pool of wild Amaryllidaceae is very rich in the centers of origin and has been explored as a source of new genes introduced into cultivated species and for the domestication of new crops useful as vegetables, herbs, medicinal plants, and ornamentals [28].

Cultivation practices were developed independently in particular regions of the Northern Hemisphere and applied to at least 20 native or introduced vegetables of Allioideae subfamily, especially of genus *Allium*. Onion (*Allium cepa* L.) and garlic are cultivated worldwide, leek (*A. ampeloprasum* L.), shallot (*A. cepa* L. Aggregatum group), and chive (*A. schoenoprasum* L.) dominate in Western and Northern Europe, kurrat (*A. ampeloprasum* L.) in Egypt and the Eastern Mediterranean, Japanese bunching onion (*A. fistulosum* L.) in Japan, rakkyo (*A. chinense* G. Don), and Chinese leek (*A. tuberosum* Rottl. ex Spr.) in China. The cultivated onion group is the result of intensive breeding and represents morphological and physiological characteristics appreciated both for cultivation and marketing. The latter include diversified shape, color, pungency, and chemical composition of bulbs, reduced bolting, long shafts in leek, fast leaf growth in chives, single heart in onion but separated in shallot [29–32]. Onions are known as a major food for preventing chronic disease [33], as a source of sulfur compounds, steroidal saponins, and flavonoids. Moreover, showing a functional food activity, they significantly contribute to the prevention of inflammatory and common lifestyle diseases [34]. Organic sulfur compounds, determining onions' pungent flavor, are the key components responsible for the therapeutic effects [35]: allicin, and ajoene, as well as volatile compounds have the ability to act as antimicrobials and antioxidants [36,37]; sulfur and phenolic compounds also show antioxidant, anticancer, anti-inflammatory activities, and can prevent chronic diseases [38]; quercetin, a bioflavonoid of onions, reveals antiproliferative and proapoptotic effects in many cancer cells, acts as a neuroprotector, and stimulates cellular defense against oxidative stress [39].

*Agapanthus* is the only genus in the subfamily Agapanthoideae, endemic in South Africa but naturalized around the world as ornamental. The Amaryllidoideae have a pronounced floricultural importance because this subfamily comprises popular ornamentals, including many spring-flowering bulbs (*Narcisuss* spp., *Galanthus* spp., and *Leucojum* spp.). They have been grown in European gardens since the ancient times, supplemented since 17–18 century with species of New World origin like *Hippeastrum* spp., or South African, like *Amaryllis* spp. or *Clivia* spp., widely cultivated as indoor plants. The Amaryllidoideae have been traditionally used as medicines to treat mental problems, primarily in Southern Africa [40]. Amaryllidoideae are the source of the isoquinoline alkaloids of unique structure, which were isolated from about 350 species, amongst more than 800 species belonging to this subfamily. Approximately 600 structurally diverse alkaloids were isolated to the date, chemically defined, and pharmacologically investigated, as possessing antibacterial, antifungal, antimalarial, antiviral, antitumor, analgesic, and acetylcholinesterase inhibitory activities [41–43]. The galanthamine was approved to date as the main treatment for mild to moderate Alzheimer's disease, acting as a selective, reversible competitive acetylcholinesterase inhibitor [44]. The lycorine, haemanthamine, and narciclasine series are leading anticancer bioagents in clinical research [45]. The

enormous structural diversity of Amaryllidoideae alkaloids has no equivalent in the Plant Kingdom and can be explained by the chemoecological activity [46].
