The Zamiaceae are woody, unbranched
or sparsely branched, palmlike, dioecious, seed-bearing trees or shrubs with thick, pithy
stems. The leaves are alternate, spirally arranged in a cluster at the summit of
the stem, frondlike, pinnately (rarely bipinnately) compound, usually stiff;
leaflets usually with numerous parallel veins, flat while expanding. The ovules and seeds are born
in one or more compact cones (megasporantiate strobili) consisting of densely
crowded, highly modified meagasporophylls, each bearing 2 ovules. Male plants produce male or microsporangiate
cones that bear many scales, each with an abundance of microsporangia scattered over the
lower surface. Details of reproduction similar to Cycadaceae. Seeds are typically large, sometimes up to the size of goose eggs.
Each "thumbnail" image below is linked to a larger photograph.
 |
Several cycads are visible in this photo. Note the somewhat tufted, pinnately compound
leaves. |
 |
Cycadaceae. While cycads in the vegetative state may bear a
general resemblance to ferns, the primary axis of a developing cycad leaf
is not coiled (circinate) as is the case with fern fronds. Note the
young, erect, non-circinate leaves in this cycad. |
 |
Bowenia serrulata, Byfield fern. This is the only cycad genus that has
bipinnately compound leaves. |
|
|
Ceratozamia hildae, bamboo cycad. Two microsporangiate strobili are visible on this male plant.
Foster Botanic Garden, Honolulu, HI. |
|
Encephalartos ferox, Zululand Cycad. Female strobilis. |
|
|
Encephalartos sp. This female plant has a very large and compact
female cone or megasporangiate strobilus. The individual megasporophylls
are more highly modified and not at all the leaf-like megasporophylls seen
in Cycas. The lower photo shows a mature, disintegrating female
cone with the lower cone scales still intact. Two large seeds can be seen
on each of the scales. |
|
|
Lepidozamia hopei, Hope's cycad. Leaf and megasporophylls from
female plant. Ho'omaluhia Botanic Garden, O'ahu. |
|
Lepidozamia peroffskyana, scaly zamia. This species produces one of the
largest female cones of any cycad. |
 |
Zamia furfuracea, cardboard palm. These female cones are much
smaller than those of
Encephalartos illustrated above. |
|
|
Zamia pumila, coontie, Florida arrowroot. 1 - male (L) and
female (R) strobili, 2,3 - male strobili, surface view, 4 - male strobilus
(x-section), 5 - female strobilus (x-section), 6 - megasporophyll (L) and
microsporophyll (R). Foster Botanic Garden, Honolulu, 2005. |
|
|
Zamia sp. Left: male (microsporangiate) strobilis.
Right: abaxial (lower) surface of microsporophyll showing many
microsporangia. |
