|Photo Dennis Stevenson|
Chigua D.W. Stev., Mem. New York Bot. Gard. 57: 169-172 (1990);
from a Spanish rendering of the indigenous Indian name for cycads (most frequently
applied to Zamia roezlii) in Panama and Colombia. Type: C. restrepoi D.W. Stev.
Described by American botanist Dennis Stevenson in 1990.
A genus in the family Zamiaceae, with two very rare
species in South America (Colombia).
Key to species
Click on the name to go to the species page.
Individual species pages will have photographs, distribution maps,
descriptions, literature references and general notes on the species.
These are not yet all in place for all species, but the database
is slowly growing.
On species pages, click on thumbnail images to see full-screen images.
links to images of type specimens held by the New York Botanical Garden (NY).
links to images of the protologue or original description
pertaining to the name.
- Pinnae 15-25 cm long, 30-50 mm wide --
Pinnae 30-35 cm long, 10-15 mm wide --
- Leaves pinnate
- Leaflets with midrib and parallel longitudinal secondary veins
- Leaflets articulated
- Megasporophyll apices faceted or flattened, not spinose
- Sporophylls in vertical rows in cones
Habit: dioecious fernlike shrubs with subterranean,
pachycaul, globose stems, with few leaves.
Leaf bases not persistent. New leaves emerging singly.
Leaves: pinnate, spirally arranged, interspersed with cataphylls,
lower leaflets not reduced to spines. Petioles with prickles. Longitudinal ptyxis erect,
horizontal ptyxis erect. Leaflets simple, with dentate margins, with
numerous bifurcating parallel
veins and a distinct midrib, leaflets articulated,
inserted near the edges of the rhachis towards the adaxial side,
lacking a differently coloured basal gland; stomata
? on both surfaces; epidermal cells elongated
parallel to long axes of leaflets. Leaves pubescent, at least
when young, with branched and simple, transparent and coloured hairs.
Microsporophylls: spirally orthostichous, aggregated into stalked
male cones and each with a simple sterile apex, which is
flattened or faceted, weakly bilobed, never produced into an
upturned spine. Each microsporophyll bearing
numerous microsporangia (pollensacs) on the abaxial surfaces.
Microsporangia opening by slits. Pollen cymbiform, monosulcate.
Megasporophylls: spirally orthostichous, aggregated into stalked
female cones. Sporophylls simple, appearing peltate with a simple
dilated apex which is hexagonal, flattened or faceted,
weakly bilobed, never produced into an upturned
spine. Ovules two (rarely three), sessile, orthotropous, inserted
on the inner (axis-facing) surface of the thickened lamina and
directed inwards ("inverted").
Seeds: subglobular to oblong or ellipsoidal, with a red,
or pink fleshy outer sarcotesta. Endosperm
haploid, derived from the female gametophyte. Embryo straight;
with 2 cotyledons that are usually united at the tips and a very
long, spirally twisted suspensor. Seeds radiospermic; germination