Cuphea Production and Management - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 289

Morphological Description of Cuphea viscosissima
and lanceolata
The leaves of both species are thin, entire-margined, opposites, and diminish in size
toward the top of the plant. Trichomes are common in leaf surfaces, the stem, and
reproductive structures. Trichomes are glandular and excrete a resinous and sticky
exudate. Inflorescences are in the terminal and axillary buds. The flower has an
elongated floral tube (hypanthium), dark purple in color, and formed from sepal,
staminal, and petal primordial. Two larger petals of dark purple color are attached
to the upper part of the end of the floral tube. Four petals, white or pink in color and
much smaller than the upper, are in the lower part of the flower tube. Plants with
white flowers occur in C. viscosissima x C. lanceolata very rarely. The fruit is a
thin-walled capsule covered by the floral tube. The capsule wall ruptures lengthwise
along their dorsal side to shed the seeds attached to the placenta. Several seeds are
formed within each capsule ranging between 6 and 20 seeds in each capsule. Seeds
are lenticular in shape, smooth, green or brown in color, and 2.5 mm long by
2.2 mm wide. Seed embryo includes two cotyledons and germination is
hypogeal [ 19 ].
Cuphea Seed Oil and Fatty Acid Composition
Cuphea seed oil is rich in MCFA such as caprylic (C8:0), capric (C10:0), lauric
(C12:0), and myristic acid (C14:0) [ 21 ]. The oil content varies greatly among the
265 Cuphea species. For instance, the oil content of C. llavea and C. wrightii var.
wrightii varies between 10.1 and 39.5 % [ 22 ]. Cuphea species also vary in their
fatty acid composition but typically will emphasize the synthesis and storage of a
single medium-chain fatty acid type [ 23 ]. For instance, Cuphea pulcherrima and
C. paintieri are very rich in caprylic acid (94 % and 73 %, respectively) [ 23 ], while
C. carthagenensis [ 24 ] and C. wrightii var . wrightii [ 22 ] both have high lauric acid,
81 % and 73 %, respectively. Cuphea lanceolata has relatively high capric acid
content (70 %) [ 24 ], while C. llavea has the highest level of caproate (92 %)
[ 22 ]. The interspecific hybrid of C. viscosissima x C. lanceolata , which the variety
PSR23 originated from, has a seed oil content typically in the range of 27.0-31.0 %
and whose fatty acid distribution typically includes 70 % of capric, 3 % lauric, 4 %
myristic, 6 % palmitic, 9 % oleic, and 5 % linoleic [ 25 ]. Cuphea oil has an iodine
value of 19.7 and a high oxidative stability of 157 h at 110 C comparable to that of
coconut oil. The content of free fatty acids (4-4.25 %) and chlorophyll (200-
260 mg kg 1 ) in the crude oil is considered high [ 26 ].