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Killer), "Early Golden" or "Bermuda Red" head
the list.

The Louisiana Bulletins repeatedly refer to cer-
tain varieties as commonly cultivated or standards
of excellence. In Bulletin 13, p. 329, it is said that
the "Georgia Yam," also called "Common Louisi-
ana Yam," is in general cultivation throughout that
State. "Southern Queen" ranks next to the
"Georgia" and "Sugar Yam" in popularity.

Bulletin 21, p. 648, confirms this, with the addi-
tional remark that the "Peabody," probably identi-
cal with the "Nansemond," and certainly the same
as "Brazilian," is very popular in N. Louisiana for
hog feed.

In Bulletin 22, p. 709, it is stated that the cut-
leaved varieties, "Sugar," "Georgia," "Spanish,"
"Barbado" and "Vineless," are considered best for
table use.

Bulletin 30 of the same station says that the "New
Jersey" and the "Yellow Nansemond" ("Missis-
sippi Yellow") are grown for Northern markets.

In 1898, Bulletin 52, p. 310, we find that the
"Georgia," "Sugar," "Pumpkin," "Hayman" and
"Vineless" are varieties everywhere preferred in
the South for table use.

In 1894, the Georgia Bulletin 25, p. 155, states that
the "Georgia Yam" is the standard of quality.

The Iowa Bulletin 47, of 1900, confirms most of
these statements.

North Carolina Bulletin 112, p. 78, states the same.
Bulletin 132, p. 319, states that the popular potato
in that region (near Raleigh) is the "Baydus" (cor-
ruption of "Barbadoes," of which there are a yellow
and a white-fleshed variety).

North Carolina Bulletin 74 contains the same

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statement, with the remark that the bulk of the pota-
toes sold as "Bardos" belong in reality to the
variety "Southern Queen."

B. The System of Classification.

At present one system of classifying the varieties
of sweet potatoes is in use among experimenters,
but none among growers in general. That used by
experimenters, the foliage system, was elaborated by
Mr. Price, of the Texas station, and reported in
Bulletins 28 and 36 of that station. It classifies the
sweet potatoes in three groups by the typical shape
of their leaves, and then describes each variety
separately. But as no key is given further than that
referring to the foliage, it is of course not possible
to determine a special variety, if the name be
unknown or doubtful; for to compare it with all
varieties described under that group and to be still
left in doubt as to whether the variety was repre-
sented at all, is of course an uncertain and unsatis-
factory method.

Mr. Price deserves great credit for introducing
some order into the previous chaos, and the writer
acknowledges that the "foliage system" of Mr. Price
was one of the early stimuli which induced him to
work on the classification of varieties.

To give an idea of how necessary it is at present
to describe certain standards closely may be seen
from the following. Below are given extracts from
various bulletins published at our experiment sta-
tions, the descriptions of one of the best-known
varieties, "Southern Queen."

Mr. Price describes it as follows :

Bound leaved, foliage pale green, sometimes
prominently notched on one side, vines very vig-

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orous, root profusely, length eight feet, tubers
obtuse, medium size, white. Reliable, much grown
in the South. Soft, damp, late.

Maryland Bulletin 33. — The Southern Queen is a
good yielder, a very handsome and salable potato.

Iowa Bulletin 47. — Southern Queen, medium run-
ner, leaves large, dense mat of foliage, tubers large,
fairly smooth, incline to run to roots. Skin greenish-
brown, rough ; flesh yellow, very wet, coarse ; not very
sweet nor pleasant. Very popular in the South.

North Carolina Bulletin 74. — Southern Queen,
very productive, good keeper, heading the list in
keeping qualities.

Arkansas Report, 1890. — Southern Queen, heavy
growth of vines, tubers large and smooth. An early

Georgia Bulletin 25. — Southern Queen. Leaves
shouldered. Foliage deep green. Vines quite vig-
orous. Tuber quite large, both round and ovoid.
Skin white, flesh grayish-white or grayish-yellow,
quality very poor, stringy, coarse, fibrous and taste-
less. Rather early and productive.

Louisiana Bulletin 13. — Southern Queen. Most
popular in the South, excepting the Georgia and
Sugar Yams. Tubers round and mealy.) Vines
very strong. Good producer. Improve in flavor
by storage.

Louisiana Bulletin 21. — Southern Queen. Large,
round ; light yellow skin and meat, fair quality ; very
early and popular ; a good potato.

Louisiana Bulletin 30. — Southern Queen, white,
rather hard, dry, late. Strong grower. Vines large
and green. Leaves large, broad, rather bluntly
pointed, and have side points.

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Flesh nearly white and rather dry. A very pop-
ular variety and good producer.

Louisiana Bulletin 36, p. 1266. — Southern Queen is
recommended for both quality and quantity.

Louisiana Bulletin 52. — Southern Queen. One of
the most productive varieties (720 bushels per acre
in last experiment), but not an excellent table
variety. Suggests an enormous amount of hog and
stock food, and should be grown largely for this

Fitz (Sweet Potato Culture, p. 9). — Southern
Queen is the earliest of all sweet potatoes. In eating
condition (near Baltimore) by the middle of July
when first dug, too wet in fall and early winter.
Root very large, light color, good keeper, vine vig-
orous, leaves large. Good quality.

So we find that the Southern Queen, one of the
best-known sweet potatoes in the United States, has
been variously characterized as round-leaved and
shouldered, foliage pale green and dark green, vines
very vigorous and medium ; tubers obtuse, round and
inclined to run to roots, medium sized, and large,
smooth, and rough ; skin white, greenish-brown, and
light yellow; flesh yellow, grayish-white, grayish-
yellow, light yellow, soft, and hard ; damp, very wet,
mealy, and dry; quality poor, fair, recommendable,
a good potato, good hog and stock food, flavor coarse,
fibrous, tasteless, yet a very popular table variety in
the South; late, rather early, very early and the
earliest of all sweet potatoes.

The writer has purposely considered chiefly the
work of the agricultural stations, in order that there
could not be the objection that the men giving the
descriptions were unfamiliar or unskilled as regards
such work. These men have been selected as efficient

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men for that kind of work, and there is no doubt but
that every one of these descriptions fits the sweet
potato known by the particular worker as "Southern

The question might well be asked : How can such
statements be reconciled? Much has been said about
the variability of varieties, yet it seems hardly pos-
sible that such changes affecting everything that is
regarded as essential in a sweet potato should occur
in the same variety. That sweet potatoes vary con-
siderably is certainly true. This is just as true,
however, with other plants long in cultivation, as,
for instance, corn, the common bean, tfie banana,
cabbage, etc. Still in all these we can distinguish
certain types, which may be variable in their repre-
sentatives, but which differ enough from each other
to be easily distinguished. So we have dent corn,
flint corn, sweet corn, pop corn; the drumhead and
Wakefield cabbage, cauliflower, Brussels sprouts,
kale, etc., and similarly different types of the bean
and banana. The sweet potato types certainly are
not nearly as distinct as those of cabbage or corn,
but they are perhaps as well marked as those of the

Now, what has been done to distinguish these

In Farmers' Bulletin 129, 1902, Mr. Nesbit says,
concerning classification :

"Classifications of varieties based on different
principles have been attempted without, as yet, res-
cuing the subject from disorder. The most elabor-
ate system, and perhaps the only one worthy of a
name, is that adopted by R. A. Price, horticulturist
of the Texas Experiment Station in 1893, which he
calls the * Foliage System.' He divides sweet pota-

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toes into three groups, having i round or entire foli-
age,' 'shoulder foliage' and * split or lobed foliage/
He says, 'If this foliage system is taken in connection
with a short description of the color of the tubers
and of the vines, there is scarcely a variety which
cannot be distinguished from all other varieties.'

4 'This system has been applied at several stations,
yet it would be quite impossible to recognize some
varieties as known in one section by descriptions
given of them according to the foliage system in
another section if the name were omitted. So
strong are the influences tending toward diversity
that the writer is convinced that no system of classi-
fication can demonstrate much value until the sup-
posed varieties are all brought together and propa-
gated under uniform conditions for several years."

Before going further into the subject, one might
well ask if there is any urgent necessity for the
classification of the varieties. The writer's reason
will be given later. In the following are quoted
the opinions of others who are practical farmers or
are otherwise interested in the subject:

In Farmers' Bulletin 129, p. 38, Mr. Nesbit, a
practical sweet potato grower of Maryland, gives
some suggestions for future experiments. In regard
to improvement of varieties he has this to say: "If
all the varieties or supposed varieties for which
merit is claimed should be collected and cultivated
for several years under favorable conditions and
with a system calculated to develop excellence,
planters might, at the conclusion of such a course,
be able to select from a few varieties of marked
characteristics such as give promise of special use-
fulness to them. The value of such work in estab-
lishing varieties and determining their relative

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worth by comparison and in opening the way for
an orderly nomenclature can not be doubted."

In North Carolina Bulletin 74, p. 3, Mr. Massey
says : ' ' There is much confusion in the nomenclature
of this vegetable. 'Peabody' and 'Early Red' are
so near alike that they may be regarded as synony-
mous; ' Southern Queen,' 'Hayman,' 'Bahamas' and
'Yams' are the same. 'Norton Yams' and 'Buck-
skins' are also identical. 'African Reds,' 'Black
Spanish' and 'Nigger Killer' are also synonymous,

In the Arkansas Report for 1890, p. 123, Mr. Ben-
nett says : "Much confusion arises with the different
varieties of sweet potatoes by the many different
names by which the separate varieties are known.
They invariably have local names in the particular
locality in which they are grown, and, as might be
expected, there is great similarity between some of
the so-called varieties."

In Georgia Bulletin 25, p. 153, Mr. Starnes: "In
grouping the different varieties of sweet potato we
have followed at the Georgia station the general
custom of arrangement with reference to the leaf,
in default of a better system. Indeed it can scarcely
be called a system at all, for the reason that the
same vine will sometimes hold half a dozen different
shapes of leaf; and while a distinction appears to
exist between the 'split leaf varieties and all others,
it is by no means easy to determine with some
varieties whether the 'round' or 'shouldered' form
of leaf prevails. Yet when we endeavor to classify
by other forms of resemblance, as shape, size, color
or quality of tuber, we are met by even worse incon-
gruities, and are forced to fall back on the 'leaf
classification,' clumsy and unsatisfactory as it is."

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Attempts have been made to erect, in addition to
the three forms of leaf generally accepted, to wit:
"Split leaf," "Shouldered" and "Round," a fourth
form, "Semi-shouldered"; but the difficulties are
too great in the way of its adoption, and hence the
regular division into "Split-leafed," "Shouldered"
and "Round" must suffice.

In Louisiana Bulletin 30, p. 1053, Mr. Burnette
says: "Much time and expense have been spent in
trying to properly classify these so-called varieties
and adopt a nomenclature which can be followed
throughout the country, but so far, only with partial

These questions give a fair idea of what others
think. Another good indication of the desire for
a uniform nomenclature are the frequent attempts
to reduce a number of varieties to a group, and the
abundant descriptions of many varieties, given in
various bulletins.

The writer's own reasons for working on a classi-
fication of varieties are as follows : The sweet potato
at present forms one of the staple crops in various
sections of our Atlantic and Gulf States. Experi-
ments have demonstrated that there is an enormous
difference between the yields of different varieties.
It is well known that there is a great difference in
the quality and market value of different varieties.
Some varieties contain a starch content of as much
as 29 per cent., and could probably be utilized for
starch. But one of the most serious drawbacks to
experiments in any of these lines is the confusion
in nomenclature. When one experimenter has
detected a desirable quality, another who tries to
verify the result secures another variety under the
same name and fails; others having sweet potatoes

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with the same name growing in their own patches,
observe and condemn, and so experimentation gets
into discredit. As the writer himself intends to
work further on the sweet potato in the future, he
feels the necessity of straightening out the nomen-
clature first of all.

Before advancing any opinion on the character to
be used in the classification, the following deserves
to be carefully considered:

All varieties of the sweet potato are supposed
to have originated from the same plant; they have
varied enormously, and so they are apt to vary more.
Therefore, a variety which fits a certain description
at present may in the course of a few years produce
certain sports which cannot be referred to the
original type. This should be expected and would
not invalidate the system of classification. These
sports belong to a new category and, unless they
have developed into a variety already known, they
form a new one. This principle seems self-evident,
but objections have been made to certain descrip-
tions, because plants in the same patch, the produce
of the same ancestors, did not agree with each other.

Then, also, no system of classification can provide
names for varieties which are in accord with all
names now in use. The example of "Southern
Queen" and the quotations from the various bulle-
tins already cited amply demonstrate this.

In naming the varieties priority of nomenclature
should be considered. This the writer would gladly
do if the labor involved were not altogether out of
proportion to the results. In 1731 Catesby tried to
reduce the varieties under cultivation in the Caro-
linas to five types. He states, as quoted, that there
were at that time a number of conflicting names for

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the varieties. In order to consider priority prop-
erly one would have to go back then to Catesby at
least. The writer has received over seventy so-called
varieties under various names, and finds himself
utterly unable to determine the majority of these
from the scanty description given in previous litera-
ture. Those varieties have been given the names
under which they were secured, unless those names
gave rise to confusion.

It must also be taken into account that certain
varieties will in all probability pro'duce normal
tubers only in certain sections, and that some varie-
ties when transplanted from one climate to another
will exhibit different characters. We find the same
to be true of other plants. Sweet corn, growing
six feet high in the Northern States and having the
ear about 2y 2 to 3 feet from the ground, will scarcely
grow 4 feet tall when planted in western Texas, and
make the ears right on the ground, in the first season.
Such may be due to one of two things : Either the
variety will not grow under the new conditions, or
it needs to be acclimated. It is, of course, probable
for that very reason, that some varieties with which
the writer has experimented should not do well in
New Jersey. Therefore, unless good typical tubers
were received from which to give the characters, the
tubers of varieties which did not seem to thrive have
not been included in the key.

Primarily, the varieties have been classified for
♦he writer's own convenience, and the intention is
to continue the work on sweet potatoes in various
directions during spare hours, as opportunity pre-

In any classification of varieties the following are
essentials ;

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The distinguishing characters must be reasonably
permanent, i. e., the great majority of the descend-
ants of the same plant grown together under normal
conditions ought to maintain uniformity in those

The distinguishing characters ought to be so clear
that they can easily be determined.

It is very desirable -in a key that it should take
up the characters in such an order that varieties
which differ but little from each other and are very
likely closely related can be easily compared. This
is perhaps best effected by using the same characters
in classifying all varieties.

As it is not always possible to determine all the
characteristics of a variety at one time, the char-
acters given should be as abundant as possible, so
that the variety may be determined even if not all
parts of the plant are present.

The key, as evolved below, was elaborated to meet
these different requirements.

The distinguishing characters, as utilized in the
key, were determined in the following manner :

Thirty-five so-called varieties were obtained from
the Agricultural Experiment Stations at Washing-
ton; Baton Rouge, La.; Experiment, Ga.; and from
Mr. Rose, of Wilmington, Del., and Mr. Trouncer,
of Wenonah, N. J. All these were planted in the
same patch at Wenonah and studied throughout the

All types of leaves produced by all varieties, as
the season advanced, were collected and pressed.
Photographs were taken of typical hills and vines
of each variety to show characteristic growth and
leaf arrangement. Careful notes were taken repeat-
edly and independently of the comparative length

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and thickness of the vines, their exact color near the
tip, the center, the base, on top, and below; the size
of the leaves, the color of young and old leaves, the
length of the petiole, the amount of hairiness on
leaves and stem, the coloration of the veins on both
upper and lower surface, the amount of latex, etc.
After the harvest the tubers were studied in regard
to size, shape, exterior color, distribution and size
of lenticels, roots, and shoots, hardness when raw,
color of flesh, wood elements, and cambium, and
relative abundance of latex. Samples were boiled
and baked of all varieties of which there was mate-
rial to spare, and observations made on the color,
odor, softness, flavor, sweetness, and stringiness of
the cooked tubers.

The great difference in the outer appearance of
foliage, stems, and tubers suggested corresponding
differences in their internal structure, and to deter-
mine the extent of such differences, slides were
prepared from fifteen varieties which could easily be
distinguished, showing the following parts : Upper
and lower epidermis of leaf, cross-sections through
the leaf, petiolar nectaries, petiole, the tip and base
of a full-grown stem, and the upper and lower part
of a tuber, and longitudinal sections through the

During the winter the writer received an abun-
dance of material from the already named stations
and also from Jamaica, India, Barbadoes, the Sand-
wich Islands, Mauritius, and Colombia. As many of
the tubers were in a rather poor condition on arrival,
the only way to save them was to plant them at
once. Accordingly all the tubers were started in the
greenhouses of the Botanical Garden of the Uni-
versity of Pennsylvania, and the entire lot planted

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out in May. The varieties, received under more
than a hundred different names, were studied in the
same systematic fashion as the thirty-five varieties
of the previous- year.

As was expected, the majority of the characters
noted proved unreliable. The abundance of the
latex and the color of the leaves, for example, while
distinctly variable with the varieties, were not con-
stant enough to be used as a characteristic. By
studying all the plants of every variety planted
(about 15-30 plants on an average), the writer came
to the conclusion that certain characters were suffi-
cient to distinguish all varieties whi6h could be dis-
tinguished at all by the closest macroscopical obser-
vation. Microscopical characters were not utilized
because they could not be easily applied, and because
the writer is not prepared to say that the micro-
scopical differences found are constant.

The character by which the groups can be sep-
arated most readily is, doubtless, the shape of the
leaf. Mr. Price recognized this in his system of
classification, and the author has adopted his terms,
"round-leaved" and "cut-leaved." The shape of
the leaves enables one to divide all varieties at hand
into five main groups.

The first group comprises all varieties with "cut"
leaves. As "cut" leaves are counted all those in
which the projecting lobes constitute almost the
entire leaf surface, so that little remains when all
the lobes are cut off at their bases by cuts perpen-
dicular to their median lines. In all but one or two
varieties it is very easy to tell whether the leaf
is cut or not ; but even if that should be impossible,
that fact does not interfere much with the determina-
tion of a variety, as will be seen later.

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The second group is formed by those varieties
which have only " round' ' leaves. By a " round' '
leaf is meant a heart-shaped entire leaf.

In the third group have been placed the " long-
leaved' ' varieties. In all well-formed, full j grown
leaves of these varieties the length of the large cen-
tral lobe, as measured along the median line .from
the base of the lobe to its tip, exceeds the greatest
breadth of the same lobe.

The "broad-leaved" varieties constitute the fourth
group. In these the greatest breadth, i. e., the base
of the central lobe, exceeds its length from the base
to the tip.

Some varieties invariably have several types of
leaves, so that it is hard to tell which shape is the
most common. All varieties which normally have
well-developed, full-grown, "round" leaves, as well
as "long" or "broad," have been classed as "mixed-
leaved" in group five.

In the key there has also been provision made for
varieties in which both "long" leaves and "broad"
leaves are frequent.

It should be kept in mind that all references to
leaves, unless otherwise stated, apply only to full-
sized leaves developed at least two months after
planting, for the first leaves developing from a tuber
are usually "round" leaves, even in varieties which
later never produce them. The writer has even
observed them occasionally on plants with normal
"cut" leaves.

Almost as characteristic as the shape of the leaf
is the size of the leaf. Weather and soil conditions
exert a certain influence on the size of plant parts ;
still, the author has convinced himself that neither
the difference between the compost soil used in

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greenhouses and the soil of a sandy New Jersey
field, nor the difference between the comparatively
dry growing season of the summer of 1905 and the
extremely wet and hot season of 1906, affected the
value pf the size of the leaf as a characteristic in the

All varieties begin the season's growth with small-
sized leaves. The largest leaves do not appear until
after two or three months of growth, and therefore
all references to size apply only to those later large

Online LibraryUniversity of Pennsylvania. Botanical LaboratoryContributions from the Botanical Laboratory of the University of ..., Volume 4 → online text (page 5 of 42)