BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Ostrya knowltonii | Knowlton Hophornbeam 



GENERAL BOTANICAL CHARACTERISTICS : 
Knowlton hophornbeam is a native, deciduous, small tree 10 to 40 feet
(3-12 m) tall with a 6- to 18-inch (15.2-45.7 cm) trunk diameter [9,23].
The trunk is usually short and divided into a number of slender, crooked
branches to form a round-topped crown [23].  The leaves are 1 to 2.5
inches (2.5-6.3 cm) long and short-pointed or rounded at the apex
[7,9,23].  The twigs are slender, tomentose at first to glabrous and
lustrous later [l9,23].  The bark is 0.125 inch (0.31 cm) thick,
shallowly furrowed and breaking into loose, small scales 1 to 2 inches
(2.5-5 cm) long [23].

Male and female flowers are in catkins [9,23].  The staminate catkins
form singly or in groups of two to three at the tips of the previous
year's branches.  They are slender, cylindrical, pendulous and 0.5 to
1.25 inch (1.3-3.2 cm) long [15,23].  The pistillate catkins are about
0.25 inch (0.6 cm) long, generally with two flowers in the axil of each
bract [23].  The fruit is a compressed ovoid nutlet [4].  The nutlet is
about 0.25 inch (0.6 cm) long, solitary, and sessile [23].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Knowlton hophornbeam reproduces by seed.  The flowers are wind
pollinated and the fruit is wind dispersed [14].  Germination is epigeal
[4].  Unless seeds are sown soon after maturity or are stratified, they
will not germinate until the second year [23].  No specific information
was available on germination rates or viability of Knowlton hophornbeam
seeds; however, information is available on eastern hophornbeam (Ostrya
virginiana) [17].  Eastern hophornbeam seeds usually germinate in the
spring the year after they are shed.  Germination capacity of eastern
hophornbeam seed is 27 to 65 percent [11].  Eastern hophornbeam trees do not
produce seeds abundantly until they are about 25 years old [17].

Knowlton hophornbeam can be regenerated by grafting [23].  Other species
of hophornbeam will sprout from the stump if cut or burned; however, no
specific information was available regarding the ability of Knowlton
hophornbeam to do so [11].


SITE CHARACTERISTICS : 
Knowlton hophornbeam is commonly found on sunny, dry, well-drained sites
in mountains and canyons and at the bases of monoliths in sandstone
areas [15,22,23,24].  Knowlton hophornbeam commonly occurs between 4,200
and 7,000 feet (1,280-2,133 m) in elevation [7,9,15,23,24].


SUCCESSIONAL STATUS : 
Specific information regarding Knowlton hophornbeam's successional
status was not available in the literature.  Eastern hophornbeam
typically occurs in late seral to climax forests.  It is shade tolerant
and will reproduce well under full shade [11].  How closely this applies
to Knowlton hophornbeam is unknown.


SEASONAL DEVELOPMENT : 
Knowlton hophornbeam flowers are produced from March through May before
or with the leaves [15,23].  The fruit of hophornbeam species matures
and is dispersed during the same season as pollination.  In most
hophornbeam species, the staminate catkins are produced the growing
season before anthesis and are exposed during the winter.  The
pistillate catkins develop in the spring with the new shoots, with
anthesis occurring as the leaves are forming [4].

Related categories for Species: Ostrya knowltonii | Knowlton Hophornbeam