PBIO 250 Lecture Notes
James L. Reveal
Norton-Brown Herbarium University of Maryland
COMMELINIDAE Takht., 1967: 7 orders, 16 families and 15,000 species. Plants mostly herbaceous to somewhat woody. Flowers mostly small and usually (more primitive) trimerous with well differentiated sepals and petals becoming (in the more advanced) reduced and chaffy. The ovary is always superior. Summary from the University of Wisconsin.
Commelinales Dumort., 1829
Commelinaceae R. Br., 1810: Herbs with succulent stems bearing leaves with closed basal sheaths, 3-merous flowers often with hairy filaments and a superior, tricarpellate, 3-locular ovary. CA3 CO3 A6 GS(3). 40 genera, 650 species. Divided into two subfamilies: Caronematoideae and Commelinoideae Eaton. Widespread mainly in tropical but occasionally in temperate regions. The stamens often with long hairs and the anthers on modified connectives. The embryo sometimes weakly dicotyledonous. Many are cultivated (Tradescantia, including Rheo and Zebrina). Cartonema is sometimes placed in its own family, Cartonemaceae. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.
Juncales Dumort., 1829
Juncaceae Juss., 1789: Tufted graminoid herbs with narrow leaves sometimes reduced to only a basal sheath, and the 3-merous flowers of scalelike tepals, six stamens and a 3-locular capsule. CA3 CO3 A6 GS(3). 6 genera, 345 species. The monospecific, shrubby African genus, Prionium, is now placed in its own family, Prioniaceae. Temperate regions and tropical mountains. Graminoid plants with 3-merous flowers, tetradinous pollen, capsular fruits and a solid pit. Juncus (225 species) is the largest genus; it is rarely cultivated. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii. See also Cardillo & Samuels.
Cyperales Burnett, 1835
Cyperaceae Juss., 1789: Graminoid herbs often with a 3-angled, solid stem bearing 3-ranked, closed sheathed, aligulated leaves, flowers subtended by a single bract and consisting of a perianth - when present - reduced to bristles or scales, and an achene or nutlet. CA0 CO0 A1-3 GS(2-3) or CA0 CO0 A1-3 G0 and CA0 CO0 A0 GS(2-3). 104 genera, 4945 species. Cosmopolitan, and especially of a temperate distribution. Divided into four subfamilies: Mapanioideae, Cyperoideae Kostel. (Cyperus, Eleocharia, Scirpus), Sclerioideae Burmeist. (Cladium, Rhynchospora, Schoenus, Scleria) and Caricoideae Kostel. (Carex). Many are used for thatching, basket making, paper making and a few for food; occasionally cultivated as an ornamental. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.
Poaceae (R. Br.) Barnhart, 1895: Gaminoid herbs often with a rounded, hollow stem bearing 2-ranked, mostly open sheathed, ligulated leaves, with the flowers subtended by a series of bracts (glumes, lemma and palea) and consisting of a perianth reduced to lodicules, producing a caryopsis. CA0 CO0 A3 GS(2-3). 694 genera, 7950 species. Truly cosmopolitan. Divided into 11 subfamilies: Anomochlooideae, Pharoideae, Bambusoideae Luerss., Ehrhartoideae Link, Pooideae Benth., Arundinoideae Burmeist., Danthonioideae, Aristidoideae, Chloridoideae Burmeist., Centothecoideae Soderstr. and Panicoideae Link. Many of the most important plants for humans belong to this family: wheat, corn, barley, rye, sugarcane and grass for feeding livestock. Some of the woody bamboos are nearly arborescent, and some of the primitive members hardly resemble true grasses in their floral structure. The family now usually placed in Poales. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii. See also Grass genera of the world by Watson & Dallwitz for generic descriptions and distribution data.
Typhales Dumort., 1829
Typhaceae Juss., 1789: Large graminoid herbs with round, solid stems bearing 2-ranked, linear leaves and a dense, cylindrical spike divided into a staminate and pistillate part, the perianth reduced to slender threads or elongated scales. CA-many CO-many A2-5 or (2-5 G0 or CA-many CO-many A0 GS1. 1 genus, 10 species. Cosmopolitan in moist and often swampy areas. The cat-tails are sometimes used in dry flower arrangements. Some authors include Sparganiaceae in Typhaceae. Full description from Watson & Dallwitz; family synonymy from Reveal; list of genera from Kew; family synopsis from the University of Hawaii.