Melothria pendula. a. Section of fruiting stem (above) and tip showing tendril (below), b. Inflorescence of staminate flowers, c. Staminate flower, longitudinally dissected, d. Floral diagram of staminate flower, e. Branch with pistillate flower, f. Advanced pistillate flower, side view, g. Advanced pistillate flower, longitudinally dissected, h. Floral diagram of pistillate flower, i. Unusual leaf form. Drawn by Priscilla Fawcett. From Correll and Correll 1982.

2004 ◽  
pp. 768-774
Keyword(s):  
Staminate Flower ◽  
Pistillate Flower ◽  
Side View ◽  
Leaf Form

scholarly journals Variation in the Onset of Flowering of Summer Squash as a Function of Days and Heat Units

1994 ◽  
Vol 119 (2) ◽  
pp. 249-252 ◽  
Author(s):  
D.S. NeSmith ◽  
G. Hoogenboom
Keyword(s):  
Cucurbita Pepo ◽  
Significant Proportion ◽  
Staminate Flower ◽  
Pistillate Flower ◽  
Single Equation ◽  
Cultivar Differences ◽  
Days To Flowering ◽  
Heat Units ◽  
Summer Squash ◽  
Time To Onset

The time from sowing to flowering and maturity of summer squash (Cucurbita pepo L.) varies depending on environment. Research was conducted over a 2-year period to assess flowering time of five squash cultivars grown at different locations and times in Georgia representing varying thermal regimes. Heat units (HUs) were calculated using a single equation to determine if this approach could account for a significant proportion of the variability in the time to onset of flowering observed over this range of environments. Depending on the cultivar and flower sex, the number of days to flowering varied as much as 20 days. There were no cultivar differences in overall mean days to first staminate flower; however, there were differences in mean days to first pistillate flower. There were cultivar differences in HUs required for staminate and pistillate flowers. The use of HUs significantly affected the variability in time to flowering as indicated by regression analyses and mean absolute differences between predicted and observed days to flowering.

scholarly journals A Revised Sectional Classification of Plukenetia L. (Euphorbiaceae, Acalyphoideae) with Four New Species from South America

2020 ◽  
Vol 45 (3) ◽  
pp. 507-536
Author(s):  
Warren M. Cardinal-McTeague ◽  
Lynn J. Gillespie
Keyword(s):  
New Species ◽  
South America ◽  
Amazon Basin ◽  
Staminate Flower ◽  
Pistillate Flower ◽  
Molecular Data ◽  
Extrafloral Nectaries ◽  
Leaf Venation ◽  
Molecular Phylogenetic ◽  
Three New Species

Abstract—We present a phylogenetic classification for Plukenetia (Euphorbiaceae, Acalyphoideae) based on morphology and molecular phylogenetic studies using nuclear (ETS, ITS, KEA1 introns 11 and 17, TEB exon 17) and plastid (matK, ndhF, psbA-trnH) DNA data. Plukenetia comprises 25 species divided into six sections, with three new sections and four new species described here. The circumscription of Plukenetia is unaltered from recent treatments and we continue to recognize Romanoa as distinct. The sections of Plukenetia correspond with the subclade system proposed by Cardinal-McTeague and Gillespie (2016): P1 = P. sect. Fragariopsis comb. et stat. nov.; P2 = P. sect. Penninerviae sect. nov.; P3 = P. sect. Plukenetia; P4 = P. sect. Angostylidium; and P5 = P. sect. Hedraiostylus + P. sect. Madagascarienses sect. nov. The sections are distinguished by a combination of leaf venation, staminate flower morphology, pistillate flower number, style morphology, fruit type, and seed size. Additionally, we describe three new species from South America belonging to sect. Penninerviae: Plukenetia brevistyla and Plukenetia megastyla from the Amazon basin and Plukenetia chocoensis from the Chocó Biogeographic Region of Colombia. The new Amazonian species are morphologically similar to P. brachybotrya but distinguished by their style shape and size. The new Colombian species is morphologically similar to P. penninervia but distinguished by its elongate basilaminar extrafloral nectaries, presence of abaxial laminar extrafloral nectaries, and longer inflorescences. We also describe a new species from sect. Plukenetia, Plukenetia sylvestris, which is found in central and southern Peru. This species is suggested to be the wild progenitor of the cultivated P. carolis-vegae, differing by its smaller seeds/fruits and fewer stamens. Molecular data, including a new ETS phylogeny sampling P. brevistyla, support our new taxa as distinct. Keys to the sections and species of Plukenetia are provided and we designate 12 new lectotypes for Plukenetia and Romanoa.

Flowering phenology and mimicry of the rattan Calamus castaneus (Arecaceae) in southern Thailand

Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 856-865 ◽  
Author(s):  
Aroonrat Meekijjaroenroj Kidyoo ◽  
Doyle McKey
Keyword(s):  
Staminate Flower ◽  
Pistillate Flower ◽  
Flowering Phenology ◽  
Floral Biology ◽  
Olfactory Cues ◽  
Floral Display ◽  
Pollination Success ◽  
Male Flowers ◽  
Intersexual Difference ◽  
And Function

In the insect-pollinated dioecious rattan Calamus castaneus Griff., nectar and pollen rewards, together with visual and olfactory cues, attract insects to male flowers. Pistillate flowers are apparently rewardless. Here, we aimed to clarify the mechanisms assuring visitation and pollination of female flowers. We studied features of flowering phenology and floral biology that affect pollination success of plants of both sexes. The results show that C. castaneus features a striking system of mimicry, quite different from those studied previously in other dioecious plants. The population of C. castaneus was not significantly male biased and no intersexual difference in number of inflorescences per plant was detected. However, male plants began their blossoming earlier and flowered longer than female plants. There was thus an excess of male floral display. This excess should increase the frequency of insect-mediated transport of pollen from male to female plants. Furthermore, on female plants each pistillate flower is accompanied by a sterile staminate flower that appears to contribute to insect attraction. Quite similar in morphology and function to fertile staminate flowers, they produce similar visual and olfactory cues, but less rewards (nectar but no pollen). C. castaneus thus ensures pollination success by intersexual phenological differences and by floral mimicry.

scholarly journals Begonia depressinerva (sect. Baryandra, Begoniaceae), a new species from Luzon Island, the Philippines

Phytotaxa ◽  
2019 ◽  
Vol 425 (3) ◽  
pp. 154-162
Author(s):  
MC ANDREW K. PRANADA ◽  
CHRISTINE JOY S. LUNA ◽  
NOE P. MENDEZ ◽  
MA. ELEANOR CALAPATIA-SALVADOR
Keyword(s):  
New Species ◽  
Leaf Blade ◽  
Staminate Flower ◽  
Pistillate Flower ◽  
The Philippines ◽  
Basal Margin ◽  
Outer Tepal ◽  
A New Species

A new peltate species of Begonia sect. Baryandra from Kidadayaig Falls, General Nakar, Quezon is described and illustrated here. The new species, B. depressinerva, is diagnosed against the morphologically similar B. tayabensis. The two species are similar by having rhizomatous stem, peltate, ovate leaf, and 5-tepalled pistillate flower, but the new species is remarkably different by having densely pilose, asymmetric leaf blade, densely pilose petiole that is inserted much closer to the basal margin, obtuse to subobtuse staminate flower outer tepal apex, and glandularly hairy ovary. B. depressinerva is proposed to be Vulnerable (VU) D1, following the guidelines of the IUCN.

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