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Atriplex
See list of 11 species in this genusThe lower leaves are important for identification. Unfortunately, they are often shed by fruiting. Most species of Atriplex produce two types of fruits—brown fruits and black fruits. The brown fruits (ranging in color from brown to red-brown or yellow-brown) are larger, compressed, possess a radical, and have a dull or barely glossy, somewhat soft outer surface. The black fruits are smaller, biconvex, barely produce a radical, and have a glossy, hard outer surface. Reference: Taschereau (1972).
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1a. Principal leaf blades coarsely dentate and with Kranz-type venation (i.e., with a fine reticulum of dark green veins, seen at 10 × magnification after scraping surface of leaf blade)
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2a. Flowers borne both in small axillary glomerules and in terminal spikes 20–50 (–110) mm long; brown fruits 1.5–2 mm long
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2b. Flowers borne in small axillary glomerules and in terminal spikes up to 20 mm long; brown fruits 2–2.5 mm long
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3a. Principal leaf blades sparsely dentate and with a pair of larger teeth near the base or ± entire except for a pair of lobe-like teeth near the base; fruiting bracteoles tuberculate and echinate on the faces
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3b. Principal leaf blades coarsely dentate (rarely some ± entire); fruiting bracteoles tuberculate to ± smooth on the faces
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1b. Principal leaf blades ± entire or with a single pair of tooth-like lobes near the base of the blade (rarely the blades sparsely and irregularly dentate, particularly near the apex) and with normal dicotyledenous venation (i.e., many vein branches free and not rejoining to form a reticulum)
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4a. Fruiting bracteoles obovate-orbicular to obtriangular, with 3–5 (–7) apical teeth [Fig. 323]; lower leaf blades oval or broad-oblong to broad-obovate, rounded to acute at the apex; fruits with the radicle apical
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4b. Fruiting bracteoles triangular or ovate to rhombic-triangular or rhombic, without apical teeth (though the lateral margins of the bracteoles may be toothed); lower leaf blades linear to triangular-hastate, acute to acuminate at the apex; fruits with the radicle basal or lateral
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5a. Inflorescence with leafy bracts nearly to tip [Fig. 324]; black fruits rare or absent
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5b. Inflorescence with leafy bracts only near base [Fig. 322]; black fruits common, sometimes even more abundant on a given plant than the larger brown fruits
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6a. Carpellate flowers dimorphic—some with no perianth and ovate-orbicular to suborbicular bracteoles and others with a 5-merous perianth and no bracteoles; fruits trimorphic—vertically oriented brown fruits, vertically oriented black fruits enclosed within bracteoles, and horizontally oriented black fruits partly enclosed in a 5-merous perianth
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6b. Carpellate flowers monomorphic, all lacking perianth but with a pair of accrescent bracteoles; fruits dimorphic—vertically oriented brown fruits and vertically oriented black fruits
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7a. Lower leaf blades linear to lanceolate or narrow-oblong, lacking a basal pair of outward-pointing, tooth-like lobes
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8a. Brown fruits orbicular, as long as wide, basally rounded; tip of radicle ascending to outwardly pointed
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8b. Brown fruits elliptic-orbicular, wider than long, basally flattened; tip of radicle inwardly curved (in part)
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7b. Lower leaf blades (and often the middle ones) lanceolate or oblong to triangular-hastate, with a basal pair of outward-pointing, tooth-like lobes (caution: the lower leaves are frequently deciduous by maturation of the fruits)
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9a. Brown fruits elliptic-orbicular, wider than long, basally flattened [Fig. 326]; tip of radicle inwardly curved (in part)
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9b. Brown fruits orbicular, as long as wide, basally rounded; tip of radicle ascending to outwardly pointed
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10a. Lower leaf blades triangular-hastate with outwardly pointed basal lobes, the base truncate to subcordate [Fig. 325]; brown fruits 1.5–2.5 mm long; black fruits 1–1.5 mm wide; bracteoles with a spongy inner layer
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10b. Lower leaf blades broad-lanceolate to ovate or triangular with outwardly or forwardly pointed lobes, the base cuneate to broad-cuneate or rounded; brown fruits 2.5–3.5 (–4) mm long; black fruits 1.2–2.9 mm long; bracteoles lacking a spongy inner layer
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11a. Obligate halophyte of coastal saltmarshes; foliage (especially the margins) and stems often conspicuously tinged with red; black fruits 2–2.9 mm long
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11b. Ruderal weed, not of saltmarshes; foliage and stems green or rarely with weak red-tinging; black fruits 1.2–2 mm long
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Each photo represents one species in this genus.