The Jepson Herbarium
		University of California, Berkeley
			Jepson Herbarium

Key to Araceae

1. Plants not reduced, clearly differentiated into stems, leaves; floating aquatics or not; inflorescence a spike, conspicuous; perianth parts 0, 4, 6; stamens 0, 2, 3, 4, 6 (genera treated as Araceae in TJM (1993), minus Acorus)

2. Plant aquatic, floating; inflorescence ± sessile, inconspicuous among basal leaves ..... [PISTIA]

2' Plant terrestrial or near edge of water; inflorescence peduncled, ± conspicuous

3. Petiole < leaf blade; inflorescence bract yellow ..... LYSICHITON

3' Petiole ± >= leaf blade; inflorescence bract sometimes pale yellow-green but not yellow

4. Peduncle ± >= leaf; inflorescence bract white both surfaces (tip generally pale green) ..... ZANTEDESCHIA

4' Peduncle generally << leaf; inflorescence bract abaxially pale yellow-green, adaxially ± white to pale yellow-green or dark purple, or green both surfaces (margins pale green to white or not)

5. Inflorescence sterile in ± upper 1/2, flowers only in lower 1/2; inflorescence bract abaxially pale yellow-green, adaxially ± white to pale yellow-green or dark purple ..... ARUM

5' Inflorescence fertile throughout; inflorescence bract green both surfaces (margins pale green to white or not) ..... [Peltandra virginica]

1' Plants much reduced, not differentiated into stems, leaves; floating aquatics; inflorescence 1-flowered, inconspicuous; perianth parts 0; stamens 1, 2 (genera treated as Lemnaceae in TJM (1993))

6. Roots 0 (see also Lemna trisulca)

7. Plant body ± cylindric to nearly spheric, 0.4–1.3 mm ..... WOLFFIA

7' Plant body flat, linear to oblong, 3–10 mm ..... WOLFFIELLA

6' Roots present

8. Root generally 1 ..... LEMNA

8' Roots generally 2–16

9. Roots generally 2–7; plant body 3–5 mm, veins 3–7; winter buds 0 ..... LANDOLTIA

9' Roots generally 7–16; plant body 5–10 mm, veins 7–12; winter buds produced ..... SPIRODELA

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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