Some species of Viburnum have, like Hydrangea, inflorescences of both small fertile and large sterile flowers. Inflorescences of Viburnum plicatum var. plicatum have peripheral flowers that attract pollinators to the tiny, fertile flowers. #Viburnaceae #Botany 🌾🧪🌱

Viburnum flowers are typically small & white, & the anthers are fused to the corolla. They are easy access for just about any insect. This is Viburnum phlebotrichum (📷: Timur Kalininsky CCBY4) of Japan, whose bowl-shaped flowers are great for pollen- & nectar-eaters. #Viburnaceae #Botany 🌾🧪🌱

The genus Viburnum has over 200 species, mostly in the northern temperate zone. They have opposite leaves, dome-shaped panicles of small flowers & red, blue or black drupes. This is Viburnum rafinesqueanum of eastern N. America. #Viburnaceae #Botany 🌾🧪🌱

Lest you think epiphytes are found only in the tropics, look to the bryophytes. Mosses & liverworts survive drought by drying without dying. They can shrivel up on dry days but resurrect in the next rain. #bryophyte #moss #liverwort #epiphyte #Botany 🌾🧪🌱

There are physiological ways of avoiding the daily drought stress of epiphytism. Many epiphytes are CAM plants, so they open their stomata only at night, when it's cooler & transpiration isn’t so harsh. Orchids, bromeliads, & hoyas (📷: H. kerrii) are familiar CAM plants. #Apocynaceae #Botany 🌾🧪🌱

Some epiphytic aroids, like this Epipremnum pinnatum, are more properly called hemiepiphytes (“half epiphytes”). They escape the daily drought by sending long roots down to the soil. These feeder roots differ from the holdfast roots that anchor the plant in the canopy. #Araceae #Botany 🌾🧪🌱

Another way to avoid the daily drought faced by epiphytes is to surround their roots with some organic matter. These Drynaria quercifolia trap moisture-holding leaf litter behind the dead shield fronds & do photosynthesis & reproduction with the green fronds. #epiphyte #Polypodiaceae #Botany 🌾🧪🌱

Many epiphytic bromeliads solve the daily drought problem by impounding water in their rosette of leaves. This is their private cistern. With this much water available, they won’t dry out. Daily drought? They don’t feel it. #epiphyte #Bromeliaceae #Botany 🌾🧪🌱

Many epiphyte roots (especially orchids) have an outer layer, the velamen, that is dead & spongy. It holds onto water until the plant can take it in. On the left, the roots are dry; on the right, the roots are still wet even though the palm trunk is dry. #roots #epiphyte #Orchidaceae #Botany 🌾🧪🌱

This Phalaenopsis hybrid growing on a palm trunk is exposed to daily rain (or irrigation) followed by daily droughts. It survives by having thick, leathery, water-storing leaves & thick roots. #Orchidaceae #Botany 🌾🧪🌱

This tree in Costa Rica shows how exposed some epiphytes can be (& still thrive). Yes, they get a daily rain shower, but it is followed by intense sunlight & wind that dries everything out. Moisture is either feast or famine, and plants must endure a daily drought. #epiphyte #Botany 🌾🧪🌱

Let’s talk epiphytes. This is Cyrtopodium punctatum, which has large pseudobulbs (swollen stems) that store water. The plant may get rain every day, but as an epiphyte without contact with the soil, it dries out quickly. It must store water to survive the daily drought. #Orchidaceae #Botany 🌾🧪🌱

When I lived in Florida, I grew Pimenta dioica, a small tree from Mexico, Central America & the Caribbean. Its dried, immature fruits are the source of allspice, so I harvested & dried my own. At the rate I use it, it may be a lifetime supply of allspice. 😂 #Myrtaceae #Botany 🌾🧪🌱

Syzygium acre is endemic to New Caledonia & is noted for its cauliflory, i.e., it produces flowers & fruits on the trunk. These are flower buds not yet open. It is also a schopfbaume (“tufted tree”), a palm-like single-stemmed tree with a terminal crown of large leaves. #Myrtaceae #Botany 🌾🧪🌱

We can’t talk Myrtaceae without mentioning Eucalyptus, which has speciated like mad in Australia. The name Eucalyptus (“true [or beautiful] cap”) describes the sepals & petals fused into a calyptra (cap) that falls away from the stamen flowers. 📷: Eucalyptus woodwardii #Myrtaceae #Botany 🌾🧪🌱

Feijoa sellowiana (formerly Acca s.), of s. Brazil, n. Argentina & Uruguay, has flowers pollinated by passerine birds (Thraupsis, Mimus, Tangara, Turdus, etc.), which consume the sugar-rich petals (we can eat them, too!). Insects can also effect pollination. #pollination #Myrtaceae #Botany 🌾🧪🌱

Melaleuca peucophylla of Western Australia was formerly placed in the genus Calothamnus, but that genus is now sunk into Melaleuca. The stamens are in clusters & form a flower adapted to bird pollination. #pollination #Myrtaceae #Botany 🌾🧪🌱

Myrtaceae flowers are often stamen flowers, i.e. stamens are showy, colorful & attract pollinators. The flowers have a hypanthium in which nectar collects. The hypanthium is the cup structure from whose rim the sepals, petals, and stamens arise. 📷: Xanthostemon chrysanthus #Myrtaceae #Botany 🌾🧪🌱

Many species of Myrtaceae have opposite leaves with a well-developed vein running just inside the margin. Many genera have inferior ovaries and fleshy fruits, like these Syzygium thalassicum, while another large group of genera has ± superior ovaries and capsules. #Myrtaceae #Botany 🌾🧪🌱

Myrtaceae leaves usually have pellucid dots, i.e., dots that are visible with transmitted light. These bodies form from several cells that coalesce & are filled with the essential oils that give the leaves their fragrance when crushed. Eucalyptus blaxlandii 📷: Sam CCBYNC4 #Myrtaceae #Botany 🌾🧪🌱

The Myrtaceae are a large, worldwide (mostly S Hemisphere) group of woody plants, many of which are familiar in cultivation: guava, eucalyptus, myrtle, Melaleuca (née Callistemon). Leaves are usually opposite & always aromatic when crushed. 📷: Melaleuca viminalis #Myrtaceae #Botany 🌾🧪🌱

All this talk of endosperm applies only to Flowering Plants (Angiosperms), which have triploid endosperm. Gymnosperms, like pines, cycads, & junipers, do NOT have endosperm. In their seeds, the nutritive storage tissue is the female gametophyte, which is haploid. #seed #Pinaceae #Botany 🌾🧪🌱

Endosperm is triploid (a unique character in Flowering Plants), but in a few lineages, the endosperm’s job is taken over by the perisperm, a diploid maternal tissue surrounding the megaspore. A classic example of perisperm is Piper nigrum. #cotyledon #Piperaceae #Botany 🌾🧪🌱

Bonus cotyledon post: If you’ve grown an avocado from seed, you’ll recognize the two massive cotyledons & the shoot that arises from between them. The cotyledons at germination are the cryptocotylar, geal, and storage reserve type. 📷: Hornbeam Arts CCBYNC2 #cotyledon #Lauraceae #Botany 🌾🧪🌱

Walnuts come close to having labyrinth seeds. The cotyledons (the edible part) are folded distinctively, but not to the degree of labyrinth seeds. 📷: Ritesh Man Tamrakar CCBYSA2 #cotyledon #Juglandaceae #Botany 🌾🧪🌱

🧵 Labyrinth seeds have cotyledons in the seed that are highly convoluted & folded & are sometimes mistaken for ruminate endosperm! It’s an uncommon condition—so uncommon, I couldn’t find good photos. #seed #cotyledon #Botany 🌾🧪🌱 1/4

New book! A Gardener’s Guide to Botany. By @scottzona.bsky.social Also, cat.

Earlier today, I posted the diagram of cotyledon exposure, position & function. Here’s a real-life example: Seedlings of Intsia palembanica have phanerocotylar, epigeal, storage cotyledons. #seed #cotyledon #Fabaceae #Botany 🌾🧪🌱

🧵 Germination varies according to cotyledon exposure, position & function. Cotyledon exposure refers to whether they are kept hidden within the seed coat (cryptocotylar) or exposed outside the seed (phanerocotylar). #seed #cotyledon #Botany 🌾🧪🌱 1/3

Even leafless plants have cotyledons (leaves & cotyledons are not homologous). This seedling of a cactus, Homalocephala texensis (📷: Wolfgang Brüsehaber CCBYNCSA2), shows the two, horn-like cotyledons. Spines (modified true leaves) are just starting to emerge. #Cactaceae #cotyledon #Botany 🌾🧪🌱

As all gardeners know, cotyledons (the pair of seed "leaves") can look very different from the true, adult leaves of a plant. The cotyledons of this Operculicarya decaryi seedling are simple & linear, but the true leaves are pinnately compound. #seed #cotyledon #Anacardiaceae #Botany 🌾🧪🌱

Not all seeds have endosperm as their storage tissue. Some seeds store the energy needed for germination in the embryo’s cotyledons. You know peanuts: the 2 halves are the 2 cotyledons. The embryonic root & shoot are the little structures at the base. #cotyledon #Fabaceae #Botany 🌾🧪🌱

Last month, I posted on homogeneous (1st photo, Veitchia arecina) & ruminate (2nd photo, Adonidia merrillii) endosperm, descriptors that apply only to albuminous seeds, i.e., those with endosperm as the food reserve. This week, I’m looking at other seed features. #seed #Arecaceae #Botany 🌾🧪🌱

I’m back from exploring Vietnam with the International Palm Society. It was an awesome adventure. 😃 Regularly scheduled programming will resume on Monday. 🌱🧪🌾 #Botany

I was thrilled to see the extraordinarily long inflorescences on Licuala bachmaensis in Mỹ Sơn Sanctuary, near Da Nang, and in the surrounding forest. It is endemic to Vietnam. #Arecaceae #IPSinVietnam #Botany 🌾🧪

Chuniophoenix suoitienensis was an exciting find below Ban Co Peak, Son Tra Peninsula near Da Nang, Vietnam. It’s a beautiful palm. 😍🌴 #Arecaceae #IPSinVietnam #Botany 🌾🧪

Plectocomia elongata is my new favorite rattan palm. It climbs into the canopy using long cirri, which are the extensions of the leaf rachises with grappling hook spines. Bach Ma National Park, Vietnam. #Arecaceae #IPSinVietnam #Botany 🌾🧪

Waterfalls and begonias! What’s not to love? I don’t have a name on this Begonia sp., and my camera doesn’t do justice to the slight metallic sheen. Phong Nha–Ke Bang National Park, Vietnam. #Begoniaceae #IPSinVietnam #Botany 🌾🧪🌱

Some more fabulous plants from Phong Nha–Ke Bang National Park, Vietnam. 1. Lanonia centralis #Arecaceae 2. Smilax sp. #Smilacaceae 3. Archidendron clypearia #Fabaceae #IPSinVietnam #Vietnam #Botany 🌾🧪🌱

Arenga caudata is highly variable. Some have wide segments; some have narrow segments. Some have undivided leaves. These were near Paradise Cave, Phong Nha–Ke Bang National Park, Vietnam. #Arecaceae #IPSinVietnam #Botany 🌾🧪🌱

A fabulous Smilax sp. from Vu Quang National Park, Vietnam. I haven’t identified this beauty yet. I’m here for the pink new foliage & discolorous leaves. 😍👏🏻#IPSinVietnam #Botany 🌾🧪🌱

Super excited to see Lanonia calciphila in Cuc Phuong National Park, Vietnam. This genus was described in 2011. It was confused with Licuala. #Arecaceae #IPSinVietnam #Botany 🌾🧪🌱

In Hanoi, Vietnam, with the International Palm Society for the Biennial. I’m enjoying seeing magnificent specimens of Citrus x microcarpa, the calamondin, left over from Lunar New Year. (The palms are coming) #IPSinVietnam #Rutaceae

Thanks for the comment. My brain and fingers were not in sync! 😳 The leaves are discolorous.

I’ll end my week-long look at Urticaceae tribe Cecropieae with this beautiful shot of the leaves of the aptly named Musanga cecropioides by Carel Jongkind CCBYNC4. Those deeply lobed leaves are very Cecropia-like. #Urticaceae #Botany 🌾🧪🌱

Myrianthus is a genus of 8 spp. from tropical Africa. It’s another pioneer species, like Cecropia. These photos are by Scamperdale (CCBYNC2). The tree is M. holstii. The multiple fruits are from M. arboreus. #Urticaceae #Botany 🌾🧪🌱

Musanga cecropioides (📷: osoandino CCBYNC4) looks, as the epithet says, like Cecropia, but this genus is native to tropical Africa. It is also a pioneer species, favoring open areas, but unlike Cecropia, it does not have a mutualistic relationship with ants. #Urticaceae #Botany 🌾🧪🌱

Pourouma minor (both 📷: Robin Heymans CCBYNC4) has simple, unlobed leaves, so unlike P. cecropiifolia that I posted earlier. Like many others in the tribe, the undersides of the leaves are concolorous (the surfaces are different in color). #Urticaceae #Botany 🌾🧪🌱

Pourouma cecropiifolia (📷: michel_cortest CCBYNC4) has leaves like those of its cousin Cecropia, but the fruits are very different. The fruits don’t coalesce to form multiple fruits. This species is from the Neotropics. #Urticaceae #Botany 🌾🧪🌱

Coussapoa microcarpa (📷: my friend Tony Rodd, CCBYNCSA2), here cultivated in Sydney, is a Neotropical strangler, much like a Ficus. Notice how some roots grow horizontally, perfect for wrapping around a host (phorophyte)… or around itself. #Urticaceae #Botany 🌾🧪🌱