The venation of the flower of Achlyphila is relatively simple in comparison
with that of Abolboda. Fewer levels therefore suffice to show the principal
features, and are shown in figures 82-87. The pedicel, illustrated in figure 82,
contains two circles of bundles. The outermost of these circles departs into the
bases of the three sepals (fig. 8:0, in such a way that five traces are present in
each sepal (fig. 84). Successive levels (figs. 84, So) illustrate that above the
level of sepal departure, the three whorls—petals, stamens, and gynoecium—
become separate at approximately the same point. As in Abolboda, the stamen
traces branch from the vein which can be demarcated as the midvein of each
petal. No traces indicate any vestige of three other stamens, or of staminodia,
which might be assumed to have been present primitively. About five traces
are present in each petal, although these probably originate from about three
traces in each petal base. The venation of the ovary is identical to that of
Abolboda, as a higher level (fig. 8(i) indicates. As in Abolboda, widening of the
petals is concomitant with branching of veins. Ridges, which fit into interstices
between the sepals, were observed on the abaxial surface of the petals, and
presence of these ridges alters the appearance of petal vascularization somewhat,
for these ridges are vascularized. The venation of the style is as in Abolboda,
except that no branching of the three veins takes place, as no appendages are present.
The similarities between Abolboda (e.g., A. linearifolia) and Achlyphila in
respect to floral venation are quite striking. The only major differences are in
the relative levels at which veins depart. Staminodia and ovary appendages
are absent in Achlyphila, and three, rather than two, sepals are present (although
some species of Abolboda also have three sepals).
Certain details of floral anatomy other than venation are worthy of description
here because of their importance in suggesting specific and generic relationships.
Some of these have been mentioned in connection wth sepal structure.
Corolla lobes, as might be expected, are thicker in their central portion than
at their margins. The maximum width of corolla lobes was found to offer a
convenient point of comparison. The corolla lobe of Abolboda linearifolia (fig.
92), like those of the other species of Abolboda, has a maximum width of approximately
four mesophyll cells. The maximum mesophyll width in corolla
lobes of Orcctanthe sceptnim subsp. occidental is (fig. 91) proved to be about
10 cell layers; these cells are much larger than those of Abolboda. In Achlyphila
distich a, the maximum width (excluding ridges) appeared to be about 8 layers,
as shown in figure 93, with a lignified sheath around veins.
In Abolboda, both corolla (fig. 92) and ovary exhibit epidermal relief. Such
relief occurs on both surfaces of the corolla lobes. The formation is not
merely a cuticular relief. The epidermal wall is raised into delicate, ridged
eminences which run, predominantly, in a longitudinal direction on the organ
concerned. These eminences are particularly prominent above radial walls of
epidermal cells. The cuticle follows outlines of the epidermal cell-wall relief.
Outlines of the cuticle, therefore, are parallel to those of the wall relief, but less
In Orcctanthe secpfnan subsp. Occidentalis (fig. 91), similar ridges were
observed on the epidermis of corolla lobes, but they are much coarser and less
detailed than those of Abolboda lincarifolia. On the ovary, virtually no relief
On petals of Achlyphihi disticha (fig. 93), no appreciable relief could be
detected on epidermal cells. On the ovary, however, there are forms of epidermal
cell relief which correspond closely with those of Abolboda linearifolia. Cuticular
relief thus suggests similarity between the two genera.
The anthers in the three genera offer distinctive points of comparison. In
Abolboda (e.g., A. lincarifolia, fig. 88), the connective is wide but thin. Between
the veins and the anther sacs, the mesophyll of the connective is spongy. The
endothecium is a single layer of cells wide. In Orcctanthe seeptrum subsp. Occident
alis (fig. 89) the connective is rounded. The endothecium is a single layer
of cells wide except at the portions of the anther sacs nearest the connective.
The endothecial cells are large, and the thickening bands are narrow. The
anthers of Achlyphihi (fig. 90) have a connective narrowed at their contact with
the anther sacs. The connective itself is relatively narrow. The endothecium
is a single of cells wide except where it is adjacent to the connective. Thickenings
on endothecial cells are relatively wide compared with those of Orcctanthe
and even Abolboda. Mention should be made of the conspicuous epidermal relief
that occurs on the surfaces of the anther sacs. This feature offers a further point
of comparison between Achlyphihi and other Xyridaceae.
The ovary crests of Abolboda, a characteristic of that genus, consist of laru'e
lignified cells. This is shown for A. sprncci in fig. 38.
Mature capsule valves were available only in Aholhoda and Orcctanthe. As
shown for .1. macrosiachya var. angustior (fig. 104) capsule valves in Abolboda
consist of thick-walled sclerenchyma. Cells at the points where loculicidal
dehiscence occurs are small and non-lignified. Likewise, the septa are not liffmfied,
at least in their inner portions, and lignification is likewise absent where
the valves are joined to the ovary base. The epidermal cells may be somewhat
radially elongate, especially opposite the septa. Tn the fruits of Orectanthe
(fig. 105) on the contrary, nullification even in mature fruits is mostly limited
to the epidermal layer. (Vlls in this layer are mostly markedly elongate radially
Ovules of all species of Ab olio da for which appropriate stages were available
showed the same features. The ovule is anatropous, with two integuments which
are distinct from each other and the nucellus well back into the chalazal region.
The integuments are each two cells wide. The megaspore mother cell is separated
from the surface of the nucellus by a single layer of cells. The ovules of
A. inacrostochi/a var. rob list ior showed some degree of wing formation, reminiscent
of the condition in Orcctanthc. Ovules of Onctanthc were insufficiently
well preserved to gain an accurate idea of their structure. They appear to be
decidedly laterally flattened, however, so that a wing, composed on one side of
the funiculus and on the other side, of the outer integument, is present. This
wing is more than two cell layers in width, and this greater width extends to
parts of the ovule other than the wing, as the several layers between epidermis
and tanniferous layers in the seed shown in figure 103 indicate. An idea of the
extent of the wing ean be gained from the figure of the seed of (). sccptrum
given by Maguire, "Wurdack et al. (1958, fig. lm). The inner integument is not
involved in wing formation.
The ovules of Achli/phila distich a- are identical in structure with those of
Abolboda acicularis and other species which lack wings; in turn, these conform
to the pattern described by AVeinzieher (1913) for Xyris indica.
The seed of Abolboda is seemingly quite complex because of the four distinctive
layer of cells. These four layers are shown in the longitudinal section (fig.
99) as well as the transection (fig. 100) and in the successive "paradermal"
(tangential) sections shown in figures 94—97. The chalazal-micropylar axis is
considered here as the longitudinal axis, and a sagittal section is considered a
longitudinal section that passes through the funiculus and bisects the ovule.
The outermost layer of the seed is collapsed, or nearly so, at maturity. The
cells are longitudinally elongate (fig. 94). These cells represent the relatively
unmodified epidermis of the ovule. The cells of the hypodermal layer (fig. 9.1,
excepting ridges) are large and highly vacuolate. They are enlarged in such a
way as to occupy the valleculae of the wave-crest conformations of the layer
beneath (see on fig. 100). The cells of the hypodermis are feAver than those of
the epidermis, and are elongate laterally (fig. 95). They lack living contents at
maturity. The two cell layers beneath the epidermis and hypodermis are distinctive
in that (1) their walls are fairly thick and composed of a substance very
refractory to staining, and (2) during their maturation stages, they first accumulate
droplets of, then are entirely filled with a resin-like or tannin-like substance
which stains bright red with safranin. The outer of these two layers (fig. 96)
consists of cells that are tangentially elongate. In places, longitudinal ridges
develop because of radial elongation of cells in this layer (fig. 100; tips of these
ridges are seen in figure 95). These account for the longitudinal ridges seen in
OTOSS aspect on seeds of Abolboda, as illustrated by Maguire, AVurdaek et al.
(1958). The outer cell wall of each cell of this layer shows a relief, which consists
of relatively large ridges. There is an adjustment, during maturation, so
that cells of the hypodermis occupy spaces between the ridges, but are exceptionally
thin atop the ridges.
The innermost layer (fig. 97) consists of more or less isodiametric cells, with
contents as noted above. Cell layers internal to this layer (i.e., nucellar layers)
are completely collapsed at maturity, and only a thin membrane of collapsed
cell walls separates the endosperm from the innermost layer just mentioned.
At the chalazal end of the ovule (fig. 98), the structure is altered. Instead of
the four distinctive layers, numerous layers are present. These consist of cells
like those of the innermost seed coat layer, with the same dense contents. They
form a sort of operculum in the seed. In immature seeds, a number of nucellar
layers which might be mistaken for a haustorium are present; during maturation
stages, these collapse. The way in which the two layers with contents are
altered at the micropyle is indicated in figure 101. The lumen of these cells is
quite small in comparison with the thickness of the wall, and a two-layered wall
condition is visible in the outer row of cells. Mention should be made of the fact
that during maturation of the seed, walls of the cells with contents are obliterated,
so that limits between these cells may be difficult to ascertain.