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An order of monocotyledons, the composition of which only recently has been revealed by deoxyribonucleic acid (DNA) sequence studies of four genes. Included are four families, two of which have been generally viewed as closely related: Pandanaceae (800 species; the screw pine family) and Cyclanthaceae (230 species; the Panama hat family). These two families have often been considered to be related to Arecales (with a single family, Arecaceae, palms), but actually the relationship is distant. In addition, the order includes Stemonaceae (35 species) and Velloziaceae (200 species), which have been thought to be related to Dioscoreaceae (Dioscoreales) and Bromeliaceae (Commelinales) or Hypoxidaceae (Asparagales), respectively. Pandanaceae are often lianas or large herbs from the Old World; Cyclanthaceae are herbs or lianas from the New World tropics; Stemonaceae are herbs or lianas of the Old World (but with one species in the southeastern United States); and Velloziaceae are herbs or small shrubs of Africa and particularly South America (with one genus in southwest China). Cyclanthaceae, Pandanaceae, and Stemonaceae have flower parts in twos or fours, which is unusual among monocotyledons, in which threes are most common.
Industry:Science
An order of monocotyledons, the well-known lilies or family Liliaceae of many previous botanists, actually consisting of 9 families and about 1600 species. Liliales are clearly circumscribed in deoxyribonucleic acid (DNA) sequence analyses, but are difficult to define on the basis of morphological characters, resulting in varying family composition in different classifications. Separation of Liliales from the lilylike Asparagales has proved particularly problematic, but they differ in nectary position (septal in Asparagales) and absence of phytomelan, a dark seedcoat pigment present in most families of Asparagales. Nearly all features marking the families of Liliales are micromorphological (for example, perigonal nectaries, nuclear endosperm formation).
Industry:Science
An order of Mycetozoia. These are slime molds which form a plasmodium, a multinucleate stage that may in some species measure a foot or more across. The plasmodium, typically found on decaying plant material, is a migratory phagotroph preying on microorganisms. A mature plasmodium is a sheet of protoplasm containing a network of channels through which rapid endoplasmic streaming occurs. Direction of flow is reversible at intervals (shuttle-flow movement), but with a net unidirectional movement of the plasmodium. The cytoplasm often contains pigment (yellow, orange, green, or other colors).
Industry:Science
An order of nematodes characterized by having the cuticle of the cephalic region doubled or formed into a cap or helmet. The helmet results from the infoIding of the cuticle over the extreme anterior end of the esophagus. The stoma may or may not possess armature in the form of teeth or movable jaws. Even though the stoma is surrounded by esophageal tissue, the anterior portion of the movable jaws is of cheilostomal origin. The well-developed esophagus is nearly cylindrical, and the esophagointestinal valve is prominent. The five esophageal glands are located in the posterior region of the esophagus; however, the orifices for these glands are located anterior to the nerve ring. The dorsal and two anterior subventral glands open at the base of the stoma or through the stomatal teeth. The amphid apertures may be transverse slits or elongate ovals. The cephalic sensilla are most often in two whorls: an anterior circumoral whorl of 6 and a posterior whorl of 10 (6 + 4); in some taxa this whorl is clearly separated into the ancestral state of a circlet of 6 and one of 4. A single medioventral excretory cell is usually present; the orifice is generally at the level of or anterior to the nerve ring. Medioventral supplementary organs may or may not be present on males. The male spicules are paired and accompanied by a gubernaculum. Caudal glands and a cuticular spinneret are found in males and females.
Industry:Science
An order of nematodes comprising the single superfamily Isolaimoidea. The order consists of one family and one genus. They are rather large for free-living soil nematodes (0.1–0.2 in. or 3–6 mm) and are found in seldom-cultivated sandy soils. Some forms have anterior annulations, while others have posterior transverse rows of punctations. The diagnostic characteristics of this superfamily are the presence of six hollow tubes around the oral opening and two whorls of six circumoral sensilla. Amphids are apparently absent, though some authors speculate that their function is taken over by the dorsolateral papillae of the second whorl. The triradiate stoma is elongate and has thickened walls anteriorly. The esophagus is clavate. The female ovaries are opposed and outstretched, and may have flexures. The gubernaculum, supporting the thickened male spicules, has two dorsal apophyses, and male preanal supplementary organs are papilloid. Paired caudal papillae are large in males, small in females.
Industry:Science
An order of nematodes comprising the single superfamily Oncholaimoidea. These nematodes are principally marine and brackish-water forms with alleged predaceous and carnivorous feeding habits. The external amphidial aperture is an oval or a widened ellipse. Generally, the stoma is armed with one dorsal tooth and two subventral teeth, and its wall may be further fortified with transverse rows of small denticles. The stoma is divisible into the cheilostome (secondary blastocoel invagination) and the esophastome (primary blastocoel invagination). In some species the stoma of the adult male is collapsed or indistinct. The cephalic sensilla are in two whorls: one is circumoral and composed of six papilliform sensilla; the second combines the ancestral two whorls of six and four into a single whorl of ten setiform sensory organs. In some forms these sensilla are papilliform. The cylindrical-to-conoid esophagus may exhibit a series of muscular bulbs posteriorly. The cuticle is generally smooth, and over the length of the body there are scattered sensory setae or papillae.
Industry:Science
An order of nematodes having a full complement of cephalic sensilla on the lips in two circlets of 6 and 10. The amphids are small and cuplike, and are located just posterior to the lateral lips; the amphidial aperture is either slitlike or ellipsoidal. The stoma is globular and heavily cuticularized, and is derived primarily from the cheilostome. The stoma bears one or more massive teeth that may be opposed by denticles in either transverse or longitudinal rows. The esophagus is cylindrical conoid, with a heavily cuticularized luminal lining. The excretory system is atrophied. Males have ventromedial supplements and paired spicules. The gubernaculum may possess lateral accessory pieces. Females have one or two ovaries. Caudal glands and a spinneret are common; however, they may be degenerate or absent.
Industry:Science
An order of nematodes in which the amphid manifestation is variable but within superfamilies some constancy is apparent. The various amphids are reniform, transverse elongate loops, simple spirals, or multiple spirals not seen in any other orders or subclasses. The cephalic sensilla are in one or two whorls at the extreme anterior. In all taxa the cuticle shows some form of ornamentation, usually punctations that are apparent whether the cuticle is smooth or annulated. When developed, the stoma is primarily esophastome and is usually armed with a dorsal tooth, jaws, or protrusible rugae. The corpus of the esophagus is cylindrical; the isthmus is not seen; and the postcorpus, in which the heavily cuticularized lumen forms the cresentic valve, is distinctly expanded. The esophagointestinal valve is triradiate or flattened. The females usually have paired reflexed ovaries.
Industry:Science
An order of nematodes in which the amphids are simple spirals that appear as elongate loops, shepherd's crooks, question marks, or circular forms. The cephalic sensilla are often separated into three circlets: the first two are papilliform or the second coniform, and the third is usually setiform; rarely are the second and third whorls combined. Body annulation is simple. The stoma is anteriorly funnel shaped and posteriorly tubular; rarely is it armed. Usually the esophagus ends in a bulb that may be valved. In all but a few taxa the females have paired gonads. Male preanal supplements are generally tubular, rarely papilloid.
Industry:Science
An order of nematodes in which the cephalic cuticle is simple and not duplicated; there is no helmet. The body cuticle is smooth or sometimes superficially annulated. Cepahalic sensilla follow the typical pattern in which one whorl is circumoral and the second whorl is often the combination of circlets two and three. The pouchlike amphids have apertures that are inconspicuous or transversally oval. The stoma is variable, being simple, collapsed, funnel shaped or cylindrical, and armed or unarmed. In most taxa the stoma is surrounded by esophageal tissue; that is, it is entirely esophastome. When the stoma is expanded, both the cheilostome and esophastome are evident. Esophagi are cylindrical-conoid. Esophageal glands open anterior to the nerve ring. Males generally have three supplementary organs, more in some taxa. A gubernaculum accompanies the spicules. Caudal glands are generally present.
Industry:Science
