|University of California, Berkeley|
|Jepson eFlora: Taxon page
Key to families | Table of families and genera
Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
|Family: Betulaceae||View Description||Dichotomous Key|
|Genus:||View Description||Dichotomous Key|
|Species:||View Description||Dichotomous Key|
Stem: trunk < 35 m; bark smooth, gray to brown; twigs glabrous to fine-hairy, red-gray; lenticels small; winter buds stalked, 0--6-scaled. Leaf: glabrous to fine-hairy; blade 3--15 cm, cordate to elliptic or diamond-shaped. Staminate Inflorescence: 5--20 cm; bracts each subtending 3 flowers, 4 bractlets. Pistillate Inflorescence: 5--20 mm; bracts each subtending 2 flowers, 4 fused bractlets. Staminate Flower: sepals 4; stamens 1--4. Pistillate Flower: sepals 0. Fruit: many, in cone-like catkin, not enclosed by bract, winged, bracts 3 mm, woody, persistent.
Species In Genus: +- 25 species: northern hemisphere, South America. Etymology: (Latin: alder) Note: Root nodules contain nitrogen-fixing bacteria; wood used for interior finishing, to smoke fish, meats.
eFlora Treatment Author: John O. Sawyer, Jr.
Jepson Online Interchange
Key to AlnusPrevious taxon: Betulaceae
Next taxon: Alnus cordata
Citation for this treatment: John O. Sawyer, Jr. 2016. Alnus, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=9113, accessed on December 10, 2016.
Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 10, 2016.