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PACIFIC SCIENCE, VoL XIII, April, 1959 
Like D. Knud semi: 
D. laxa (a few uniseriate hairs on lower 
surface) . 
D. molokaiensis (thicker outer walls on 
upper epidermis). 
D. reticulata (thick-walled upper epi- 
dermis; uniseriate hairs frequent on 
both surfaces, especially in the 
grooves overlying veins on the 
upper surface). 
2. D. railliardioides (Fig. 2). Leaf bifacial; 
cells of upper epidermis larger than those 
of lower epidermis; prominent grooves on 
upper surface above major veins; 2 pali- 
sade layers present; sheath extensions 
present on many larger veins; fibers com- 
mon at both poles of larger veins; 4 secre- 
tory canals in outer portion of bundle 
sheath of larger veins, 1 or 2 near smaller 
veins; scattered uniseriate trichomes on 
lower surface and margins (upwardly 
appressed). 
Like D. railliardioides: 
D. magnifolia, D. microcephala, D. 
plantaginea (virtually identical with 
D. railliardioides). 
D. paleata (sheath extensions on ma- 
jor veins only: fibers more common 
at phloem pole of veins; secretory 
canals absent; numerous uniseriate 
hairs on both surfaces). 
D. ternifolia (fibers more common on 
phloem face of bundles). 
D. scabra, D. ciliolata, D. lonchophylla, 
D. linearis, D. Sherffiana, D. thyrsi- 
flora (upper epidermis very large 
celled; bundle-sheath extension on 
midvein only; fibers mostly on 
phloem face of bundle; usually I 
secretory canal above xylem pole of 
larger veins). 
D. platyphylla (fibers at phloem face of 
bundles only; secretory canals ab- 
sent; biseriate glandular hairs with 
large multicellular capitate heads 
and long stalks abundant on both 
surfaces; uniseriate hairs absent). 
3. D. latifolia (Fig. 3). Leaf bifacial, thin; up- 
per and lower epidermis cells of approxi- 
mately the same size, very thick walled; a 
single layer of cells weakly defined as 
palisade; bundle-sheath extensions fre- 
quent, consisting of isodiametric to fiber- 
like sclereids, although no "bundle cap" 
fibers are present on the vascular bundles: 
I or 2 secretory canals present within the 
bundle sheath or sheath extension of many 
veins; hairs absent at maturity. 
Like D. latifolia: 
D. laevigata (sclerenchyma of bundle 
sheaths and sheath extensions con- 
sisting of thick-walled fibers; secre- 
tory canals absent), 
4. D. waialealae (Fig. 4). Leaf bifacial; cells 
of upper and lower epidermis of about the 
same size, very thick walled; I or 2 layers 
somewhat differentiated as palisade; sheath 
extensions present only on midvein; prom- 
nent strands of thick-walled fibers on 
phloem face of veins, also on xylem pole 
of larger veins; secretory canals absent; 
large uniseriate trichomes abundant on 
upper surface and on margins. 
5. D. Menziesii (Fig. 5). Leaf somewhat iso- 
lateral (stomata frequent on upper surface; 
adaxial palisade cells short, nearly isodia- 
metric; cells on abaxial face like adaxial 
palisade cells in shape, with more nu- 
merous chloroplasts than cells in the cen- 
tral portion of the leaf); leaf very thick; 
bundle-sheath extension only on midvein; 
large groups of fibers on phloem face of 
veins (a few fibers on xylem pole of 
larger veins); secretory canals infrequent, 
I or 2 in bundle sheath of larger veins 
near leaf base; thick-walled uniseriate 
trichomes scattered over both surfaces and 
margin of leaf. 
Like D. Menziesii: 
D. Hillehrandii (nearly identical with 
D. Menziesii). 
D. arborea (fibers lacking near veins; 
biseriate glandular hairs present on 
both leaf surfaces). 
