Floral traits
To understand the floral traits
of H. mutabilis , 30 bagged flowers from 15 plants were examined
on
10 October 2023. The Flowers are single- or double-flowered on a 5~8 cm
pedicel on the upper branches
(Fig. 1A). The H. mutabilis flower displays a color change from
white to red (Fig. 1B). First, corolla diameter, corolla height, sepal
length, sepal width, petal length, petal width, stamen length, pistil
length, ovary height, and ovary diameter of each flower were measured
with a digital calipre to 0.01
mm. The base circumference was measured by a thread, then the longth of
the thread was determined by a digital caliper to 0.01 mm. The anther
and ovule number of each flower were counted. To examine the production
of pollen grains per flower, the anthers of each flower were dissected
and washed in 400 mL of distilled water to dislodge the pollen grains
from the anthers.
The
suspensions were stirred for 2 min, and three 1-mL samples of suspension
were drawn respectively on the plankton counting chambers, after which
the number of pollen grains in the samples was counted under a light
microscope at ×10 magnification. the pollen count of the three
sub-samples (1 mL each) was averaged and multiplied by the dilution
factor (400) to obtain the total number of pollen grains per flower. To
evaluate the production of nectar volume per flower (open one day),
nectar volume was measured using 10-μL glass microcapillary tubes during
the period of 17:00~18:00 p.m. on 10 October.