Update 6/6/2016. Made the table scrollable for computers and phones. I took help from this
page
.
Update 4/20/2016. Reducing column numbers to fit new format
Update 11/2/2015. Added Contributors column.
Update (10/2/2015): Added plants that were observed in India, in August 2015. I also have an extensive analysis of trichomes of the Indian plants. Please visit
here
for more details. Largest pollen 120 microns and smallest one about 3 microns. The average is about 41 microns. Here is a
histogram
of the size distribution.
Update (6/8/2015): Added 17 more plants. Table format revised. Plants grouped based on broad taxonomic relationships. Pollen sizes added for most of the new entries. Need help for identification in more places now.
Update (4/26/2015): About 10 more plants added, names revised. Some are not known to me. If you know of them please help. Also minor change in protocol and table format.
April 12 (first post): Continuing from my earlier post and inspired by several others who have been diligently taking pictures of flowers and pollen in the foldscope microcosmos page, I thought I would collect as many different types of pollen as possible from the domesticated and wild flora around me (North-east USA), so that I could compare them with my pollen traps. At first, all I did was to pick the flower, foldscope the petal and stain the pollen with a dilute solution of safranin O (.05%). However after looking at some 10 flowers, I realized that the staining process was altering the pollen shape ( see this post for details ). So I have now moved to making a .05% Safranin in Glycerine (purchased from a local pharmacy). The purpose of the glycerine is just hydration for the pollen to take a more full shape, the dye just adds contrast. More precisely, I drop the petal and pollen on a glass slide, and put a transparent tape on it (the paper slides are great too) to get the details of the petal and unstained/untreated pollen, and then I lift up the tape, put a drop of Safranin in glycerine, spread it around and foldscope it again. Glycerine is messy, so here are a few suggestions. Drop the glycerine on the slide and cover it with a coverslip. Wrap it in a paper towel and place a weight of about 3-5 g for about 20 minutes to remove excess glycerine, wipe the edges, and then seal the ends with tape.
After commencing with great gusto, I realized that this would be a never ending endeavor, and sometimes each flower or plant has many other interesting features. More embarrassingly, my botany is weak and so I thought it would be great to collaborate with the community to annotate the plants or even add to the table. You can send me pictures and details (Your names will also be listed on the table, see comments for sending). Include a picture of the flower, a foldscoped petal and a foldscoped pollen untreated and if possible treated with glycerine (with stain optional). I also plan to add pollen morphology and other features that catch my attention into the notes.
I realized that for this to be comprehensive, the only way out was to be systematic and so I decided to organize my observations as a table using simple html , This can be constantly updated as my own botany improves. I find this easier than combining it as a picture in picasa (which is what I was doing, and have also done here for some pictures). Also, after the first iteration of this process, I now realize that it is important to view untreated pollen to see the extent of hydration or staining. This page will be constantly updated and hopefully with your inputs the protocols, methods and presentation will only improve. Looking forward to your feedback. Lets do this together.
Notes: For pollen classification, I am using the following website . There is also the comprehensive Pollen EM database . For North American flowers, I am using the connecticut wild flower database .
Click on thumbnail for high-res image. Table is scrollable horizontally. Computer users click on the table and use your arrow keys. Phone users swipe the table to see more columns.
Flower | Flower Petal | Untreated pollen | Hydrated/stained pollen |
Common/Species name
(Family) |
Contributed by | Notes |
---|---|---|---|---|---|---|
Angiosperms | ||||||
Monocots | ||||||
Daffodil (
Narcissus
(Amaryllidaceae) ) |
LI | Most common flower in early spring. National flower of Wales. In honor of an old favorite poem of Wordsworth. “I wandered lonely as a cloud…” Pollen size ~65 microns . | ||||
Spider lilly
(Amaryllidaceae) |
LI | Observed in Chennai, India, August 2015. Didnt get very good shots as it was done on the fly. Pollen size ~ 50 microns. | ||||
Some kind of spiderlilly
(Amaryllida) |
LI | Observed at a tea shop in Valparai, India, August 2015. Pollen size 20-25 microns. Nice yellow color. | ||||
Muscari; Grape Hyacinth
(Asparagaceae) |
LI | Commonly observed in gardens early spring. Flowers in a raceme. Sticky substance in flower. | ||||
White Hyacinth
(Asparagaceae) |
LI | Fleshy white flowers on raceme, with lots of liquid when cut. Also seems to cause mild irritation when held for long (perhaps oxalic acid). Hydrated pollen show the different steps in the hydration process. Stains are taken up late in the hydration process. | ||||
Tuberose,
Polianthes tuberosa
(Asparagaceae) |
Mita li Patil | For more details see Mitaali’s post | ||||
Western Blue-eyed Grass; Sisyrinchium bellum;
(Asparagaceae) |
Joshua Guild | For more details see Josh’s post | ||||
Hosta; Arum-like
(Araceae) |
Manu | Flowers arranged on a fleshy spadix. And pollen stuck together. For more details, read Manu’s post | ||||
Hosta; Funkia
(Asparagaceae) |
LI | Commonly found as a household ornamental. Blooms late spring (June) in DC area. Note the petals retain a lot of water. | ||||
Dicots | ||||||
Dandelion; Taraxacum officinale;
(Asteraceae) |
LI | Blooms Early-Mid-spring. Rapid cycle. Commonly found as weed and on road sides. Only ray florets. Spherical pollen where exine shows spiny structures. | ||||
?
(Asteraceae) |
LI | Compositan flower that blooms late spring on roadsides. White disk floret petals. Pollen size ~ 10 microns. | ||||
?
(Asteraceae) |
LI | Observed in topslip, Tamil Nadu, August 2015. The stamens of the ray florets are full of trichomes. Pollen size ~20 microns | ||||
Centratherum punctatum
;
(Asteraceae) |
LI (Identified by inaturalist Lek ) | Observed in Parambikulam tiger reserve, India, August 2015. Purple compositan. Two types of trichomes on petals and one type on stamen. Pollen size ~20 microns. Probable invasive species | ||||
Untreated pollen | ? (Unknown family) | LI | Blooms early spring, dc area. Possibly a cherry. Didnt observe too many details. | |||
Purple/Red deadnettle; Lamium purpureum
Lamiaceae |
LI | Commonly observeweed and in wild. Blooms early to mid spring. About 6 inches tall. Extensive trichomes of a single type all over. Flowers early spring. Pollen tubes in some of them. Note hydration of pollen with Glycerine for > 30 minutes makes them spherical. | ||||
Indian privet (
Clerodendrum inerme)
also ( Volkameria inermes ) (Lamiaceae formerly Verbenaceae)) |
LI | Common ornamental observed in Chennai, August 2015. Large purple pollen. Size ~40-50 microns. Apparently has medicinal properties | ||||
Periwinkle (
Vinca minor
)
(Apocyanaceae) |
LI | Creeper, blooms early spring, dc area. Lots of pollen per flower. | ||||
Common oleander/???? (
Nerium oleander
)
(Apocyanaceae) |
LI | Observed in Chennai, August 2015.Commonly grown garden plant in chennai and also the source of floral offerings to dieties. Known to be toxic. Stamens have trichomes. Pollen ~30 microns. The corolla tube had a second set of petals with pink streaks. Incredibly trichomes are seen emerging from the pink part to the white and more so towards the base of the flower. Why this asymmetry? | ||||
Oleander/???? (
Nerium oleander
)
(Apocyanaceae) |
LI | Yellow Arali observed in Chennai, August 2015. The yellow Arali has spear-like trichomes at the base of the petal. Large pollen ~ 90 microns | ||||
Forsythia
(Oleaceae) |
LI | Shrub, flowers early spring, dc area. | ||||
Parijatam/?/coral jasmine (Nyctanthes arbor-tristis)
(Oleaceae) |
LI | A plant grown all over Chennai and used for making floral offerings to deities (Observed August 2015). It blooms at night. The flower doesnt last long when plucked and fades away rapidly by day. It has white petals and an orange petal stalk. A trichome was observed in the orange part. Pollen ~ 60 microns. Official flower of the State of West Bengal, India. | ||||
Jasmina magniflora (Oleaceae) | Mitali Patil | From Ratnagiri, India. For more details refer to her post | ||||
Cherry (
Prunus serrulata
)
(Rosaceae) |
LI | Flowers early spring, dc area. The untreated pollen has a nice yellow color. After staining the pollen swells up and it appears that the outer wall may even rupture. For example, in the stained specimen, there is a small sphere next to the big one, the small one is likely the broken exine of the pollen. | ||||
Portugal Laurel
(Rosaceae) |
LI | Blooms mid spring. Flowers on a spike. Note that even though it is related to the cherry, the pollen shape is so different. Flowers Mid-spring | ||||
Wild rose? (
Rosa
)
(Rosaceae) |
LI | Looks like a wild rose to me with sweet smelling flowers. Blooms in gardens and in parks mid spring. Pollen 30-40 microns in size. | ||||
Spring beauty(
Claytonia virginica
)
(Portulacaceae) |
LI | Observed in Great Falls, MD, early spring. Pollen inaperturate and easily observed in the purple anthers without staining. Pistil very pretty with many projections in the style. Observed pollen on pistil. | ||||
Untreated pollen |
?
(?) |
LI | Observed in Great Falls, MD, early spring. Stained the pollen with a very very dilute safranin but the structure was very clear. | |||
Untreated pollen |
?
(?) |
LI | Observed in Great Falls, early spring. Looks like strawberry, but am not sure. | |||
Magnolia virginiana
(Magnoliaceae) |
LI | Blooms early Spring. Large flowers with rubbery tepals and a sweet smell. | ||||
Southern Magnolia (
Magnolia grandiflora
)
(Magnoliaceae) |
LI | Blooms late spring and early summer. Flower has a sweet, lemon-like smell. Very large tepals and thick leaves. Pollen about 80 microns in size. | ||||
Speedwell (
Veronica
)
(Plantaginaceae) |
LI | Tiny flower, less than an inch. Petals with blue streaks. Interesting trichome pattern in petals. Trichomes only present in one half of the petal. Nice blue anthers (see first picture in hydrated pollen). | ||||
Bakopa
(Plantaginaceae) |
LI | Petals have trichomes closer to the base, perhaps glandular. Blooms continuously starting mid-spring. | ||||
Rhododendron
(Ericaceae) |
LI | Blooms early spring. | ||||
Azalea-? (
Rhododendron
)
(Ericaceae) |
LI | There is a homeotic mutation in this flower where 1-3 stamens form a petal above the anthers, as reported in a previous post . Blooms in mid-spring Pollen about 20 microns in size. | ||||
?
(?) |
LI | Pollen with nice surface features. | ||||
Red Maple (
Acer rubrum
)
(Sapindaceae) |
LI | Blooms early spring. Red pigment easily leaks out. | ||||
Goldenrain tree/Pride of India (
Koelreuteria paniculata
)
(Sapindaceae) |
LI | Blooms late spring and starts fruiting early summer. Four petals asymmetrically distributed growing on a panicle. Fruit is a bladder-like pod. Base of some petals have orange spots. Beyond the orange spots at the very base of the petal are long trichomes in a very dense thicket. Pollen size ~ 20 microns | ||||
Curry Flower Murraya koenigii (Sapindaceae) | Mitali Patil | From Ratnagiri, India. For more details refer to her post | ||||
Stained pollen |
Birch (Betula)
(Betulaceae) |
LI | Blooms early spring. | |||
Flowering dogwood (
Cornus florida
)
(Cornaceae) |
LI | Flowers mid-spring. 4 Bracts surrounding tiny flowers. | ||||
?
(?) |
LI | Some kind of mint with really pretty petals. Trichomes in petals at the base nearer to the stamens and pistils. | ||||
Common yellow woodsorrel (
Oxalis stricta
)
(Oxalidaceae) |
LI | Heart shaped trifoliate leaves, that closed when plucked. They apparently close at night. Also used in cooking imparting a tart taste. | ||||
?
(?) |
LI | Green flowers in a cluster. Blooms mid spring | ||||
Honeysuckle (
Lonicera japonica
)
(Caprifoliaceae) |
LI | Mid-spring bloomer that continues into late spring and possibly summer. Nice perfumed flowers. Usually found as a weed. Fairly large pollen (50 microns) with interesting surface features. Trichomes all over the anthers and at the base of the petal. Trichomes quite long ( ~300 microns) | ||||
Black locust (
Robinia pseudoacacia
)
(Fabaceae) |
LI | Blooms mid-spring. Fairly large trees. Sweet perfumed flowers in a cluster. Typical legume flowers with each petal of distinct size. | ||||
White clover (
Trifolium repens
(Fabaceae)) |
LI | Commonly found in lawns. Starting blooms late spring, dc area. Flowers in a bunch at the tip of a flower stalk/peduncle. Flower show a typical legume-like asymmetry. Blooms mid-spring. Pollen size ~ 30 microns | ||||
Peacock flower (
Caesalpinia pulcherrima
)
(Fabaceae) |
LI | Small shrub observed in Chennai, August 2015. Stamens are extra long. Large pollen in tetrads (~50 microns in size), like the Catalpa pollen. Are these closely related or is this convergence? Convergence I think. Didnt observe any obvious trichomes. | ||||
Golden shower tree/Kannikonna (Malayalam) (
Cassia fistula
)
(Fabaceae) |
LI | State flower of Kerala observed in Chennai, August 2015. Blooms around Onam. Flowers in a raceme and look like a grape-bunch. Although there are multiple types of anthers, I could get pollen from the tallest and the some of the smaller ones. Pollen size ~ 40 microns. I didnt realize during sampling that some could be sterile. A single trichome type in petal. | ||||
Flambuoyant tree (
Delonix regia
)
(Fabaceae) |
LI | A kind of Gulmohar tree. Caesalpinid legume observed in Chennai, August 2015. Commonly found across Chennai. One of the leaves shows variegation in the petal color suggestive of gene silencing. Large yellow pollen with rough surface and ~50 microns in size. Trichomes only on pistil (Need a better pic) | ||||
Flame of the forest/????(
Butea monosperma
)
(Fabaceae) |
LI | Was in full bloom in the month of August, 2015 in Valparai. Striking tree. Flowers have leathery petals with large pollen (~40 microns). A very interesting trichome shape was observed. See this post for more details. | ||||
Touch me not (
Mimosa pudica
)
(Fabaceae) |
LI | 3-5 micron pollen. Smallest pollen I have seen this far (I had to get a shot of two pollens side by side to get a size estimate). The plant was at the edge of the Parambikulam Tiger reserve (August 2015), definitely an invasive species, though not as prevalent. Stamens dominate the flower. Only got an image of the stalk of the stamen. Couldnt really see any trichomes on the fly. | ||||
Ononis natrix (Fabaceae) | Mitali Patil | From Ratnagiri, India. For more details refer to her post | ||||
?
(?) |
LI | Very itchy plant, probably Rosaceae. Trichomes all over the petals and leaves. Petal trichomes over 500 microns long. Pollen size ~ 40 microns. Weed like distribution. Blooms mid-spring | ||||
Catalpa
(Bignoniaceae) |
LI | Blooms late spring. The tree was over 50 feet tall. Petals have some interesting color transitions. Pollen in some kind of tetrads ~ 50 microns. A little thrip was seen in the flower. | ||||
Trumpet vine (
Campsis radicans
)
(Bignoniaceae) |
LI | Blooms late spring and continues blooming through summer. Fairly large orange trumpet shaped petal. There was several thrips in it. Lots of liquid/nectar at the base of the trumpet. Petals also had large stomata-like openings at the base, wonder if the nectar is secreted through it. Pollen size ~ 50-60 microns. | ||||
Yellow trumpet bush (
Tecoma stans
)
(Bignoniaceae) |
LI | Observed in Chennai, August 2015.Commonly grown as a shrub. South american import. Trichomes all over petal and along edge. One of the versions had a homeotic mutation where the stamen was convered to a petal. I couldnt get any pollen and so I have inserted the homeotic mutation, where one of the stamens has been transformed into a petal. | ||||
Trumpet tree (Tabebuia berteroi)
(Bignoniaceae) |
LI | Observed in Chennai, August 2015. Most remarkable trichome distribution. The Yellow part of the corollar tube has several trichomes. The purple top has branched trichomes at the edge. Pollen ~ 30 microns in size. Imported species | ||||
Indian cork tree (
Millingtonia hortensis
(Bignoniaceae)) |
LI | Extremely fragrant flowers observed in Chennai August 2015. Trichomes all over the petal and can be seen quite visibly. They are usually branched. The distinguishing feature of the petals are that there are four of them and one of them is cleaved/clefted. Pollen ~40-50 microns. | ||||
?
(Fabaceae) |
LI | Blooms late spring. Fabaceae is my best guess based on leaf and flower shape. Pollen size ~20 microns. | ||||
Nightshade (
Solanum dulcamara
)
(Solanaceae) |
LI | Purple flowers with berries. Petals have two green “eyes” at the base. The cells around the central vein are rectangular. They are distinguished from the even more toxic deadly nightshade by their floral arrangement. Fused stamens with a carpel sticking out from the center. Pollen ~ 10-15 microns. Easily released even with a gentle push. | ||||
Datura/Angel’s trumpet (Datura sp.)
(Solanaceae) |
LI | Observed in Chennai, August 2015.A toxic/medicinal plant commonly found on the roadside. Petal thick and leathery. Pollen size ~40-50 microns, Trichomes along edge of petal. | ||||
Japanese Stewartia (
Stewartia pseudocamellia
)
(Theaceae) |
LI | Blooms late spring. Plant 6 feet tall and attracts bees. The white petals have a mild fragrance and leathery in texture. Sepals covered entirely in trichomes. Flower neatly falls off with the carpel on the plant which develops into a dehisced grey fruit with five-fold symmetry. Pollen ~50 microns. Thrips associated with the flower in addition to bees. | ||||
Tea (
Camellia sinensis
)
(Theaceae) |
LI | Flower picked from Valparai, India in August 2015. A lone flower. Lots of stamen, nice yellow pollen of size about 40 microns. | ||||
Japanese camellia(
Camilla japonica
)
(Theaceae) |
Honomi | For more details refer to @Honomi’s post | ||||
Scarlet Pimpernel (
Anagallis arvensis
)
(Primulaceae) |
LI | Blooms towards the end of spring and continuously over summer. Flowers about a 1/4 inch wide and nice scarlet color. . When the sun is bright and the sky clear the flowers are open . At other times, during a rain or when the sky is somewhat overcast, or early morning and in evenings, the petals are closed. Also known as Shepherd’s weatherglass. Glandular trichomes along petal edge that is not touching adjacent petals. | ||||
Neem (Azadirachta indica)
(Meliaceae) |
LI | Observed in Chennai, August 2015.Flowers in a panicle. One of the hairiest petals with two types of trichomes. Pollen 40-50 microns. It struck me that the pollen were so large for such a small flower. | ||||
Wild sage (
Lantana camara
)
(Verbenacea) |
LI | Common invasive species in Valparai. Observed in August 2015. Trichomes of two types were seen. Pollen size 40-50 microns. See previous post for more details on the invasive species problem | ||||
Dew flower/Spiderwort (Trandescantia)
(Commelinaceae) |
LI | Spiderwort, observed in a closed state at Pollachi, August 2025. Remakrable trichomes that reminds me of a midnight exploration of this plant with Manu at the National geographic building, DC area. Pollen size ~40-50 microns. | ||||
Sapphire showers (
Duranta erecta
)
(Verbenaceae) |
LI | Observed at Pollachi, India in August 2015. Pollen size 30-40 microns. remarkable trichomes at edge of petal. An invasive plant species in India. | ||||
Stained pollen | Hibiscus(Malvaceae) | LI | Observed in the suburbs of Pennsylvania, July 2015. Giant pollen ~120 microns. The petal cell shapes differ between the light orange and the dark orange parts. | |||
Hibiscus(Malvaceae) | Paul Joseph | Hibiscus from Kochi, India. For more details refer to post | ||||
Althaea Cannabina (Malvaceae) | Mitali Patil | From Ratnagiri, India. For more details, especially related to interesting trichome patterns refer to her post | ||||
Crape Myrtle (
Lagerstroemia sp.)
(Lythraceae) |
LI | Blooms last for long from end of summer to end of fall. Petals in many colors. Pollen size ~40 microns | ||||
Vygies ( Mesembryanthemum clavatum) (Aizoacea) | Lydia-Marie Joubert | Spectacular succulents growing in the middle of a desert. For more details refer Lydia’s post . | ||||
|
Stained pollen |
Pig-face/Ice-plant (Carpobrotus)
(Aizoaceae) |
Manu Prakash | Interesting trichome patterns and physiological adaptations. For more details, refer Manu’s post . | ||
|
Impatiens balsamina (Garden balsam) (Balsaminaceae) | Maithili Sawant | Interesting exploding pods. For more details, refer Maithili’s post . | |||
?
(?) |
LI | Observed between Coimbatore and Pollachi, August 2015. Pollen size 40-50 microns, quite an interesting shape. At least two types of trichomes. One with a spherical top and the other one straight. | ||||
?
(?) |
LI | White flower with a yellow center observed in Chennai, India, August 2015. Pollen size 20-25 microns. The edge of the petal had bumps that might be trichomes but am not too sure they are. | ||||
Flower |
?
(?) |
LI | Flower from a succulent plant observed at R. Bhanumathi’s place, Chennai, in August 2015. Dont have a picture of the plant but they show wonderful pollen and trichomes. The flower may have been 1/2 inch wide while the orange pollen was about 50 microns in size. The succulent petal shows some purple spots. No picture of flower though. | |||
?
(?) |
LI | Observed in Topslip, India, August 2015. Really large pollen ~60 microns in size. Two types of trichomes, one of which is beautifully branched. | ||||
Gymnosperms | ||||||
Flower | Petal image | Untreated pollen | Hydrated/stained pollen | Common/Species name (Family) | Contributed by | Name/Notes |
Spruce (Piceae)
(Pinaceae) |
LI | 1. Resin released upon plucking of the male cone. Fairly large pollen (50 microns). | ||||
(Pinaceae) | LI | 2. Pollen ~ 50 microns. | ||||
Work in progress | ||||||
Name | Petal image | Untreated pollen |
Green Chilli pepper (Capsicum sp.)
(Solanaceae) |
LI | Name/Notes | |
Name | Petal image | Untreated pollen | Stained pollen |
Name
(Family) |
Contributed by | Name/Notes |