🌴 Scott Zona, Ph.D. 🌴

A cat standing on A Gardener’s Guide to Botany. By @scottzona.bsky.social

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

Also, cat.

I did a Google Scholar search of "Cotyledon functional traits ecology" that pulled up several papers that might be of interest. They will, I'm sure, lead you to more.

😱 Why? No need.

I know there have been some studies on ecological correlations, but I'd have to read up to tell you anything definitive.

Photo of potted plants on a greenhouse bench. The plants are seedlings, several per pot, that have their cotyledons above ground, but the cotyledons are not expanded and leafy. They are thick and pale. The shoots above the cotyledons have pinnately compound leaves.

Same photo, but with text and arrows showing the cotyledons.

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 🌾🧪🌱

Drawing showing seedlings with 5 cotyledon variations. PER = phanerocotylar epigeal with storage cotyledons; PEF=phanerocotylar epigeal with foliaceous cotyledons; CHR = cryptocotylar hypogeal with storage cotyledons; and CER = cryptocotylar epigeal with storage cotyledons.

Cotyledon function can be either leafy & photosynthetic (foliaceous) or thick & fleshy (storage reserve). Here’s a graphic from prometheusprotocols.net. https://bit.ly/4rVsxXV
This graphic does not show every variation. The key to the abbreviations is in the alt text.
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Cotyledon position can be at or below ground level (hypogeal) or above ground (epigeal). Cotyledons at ground level are sometimes called geal.
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🧵 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 🌾🧪🌱
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Yes, needles are just very narrow leaves.
Hope you enjoy the book!

Close-up photo of a cactus seedling. The seedling is fleshy and succulent. The cotyledons are opposite and horn-like. Spines are emerging from the seedling apex.

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 🌾🧪🌱

Photo of a seedling emerging among the leaflitter. The two opposite cotyledons are green, leafy and linear in shape. Two adult leaves (and one just emerging) show that the adult leaf morphology is pinnately compound.

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 🌾🧪🌱

Photo of a handful of roasted, shelled peanuts in the palm of a hand. Some are split into two halves (the cotyledons).

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 🌾🧪🌱

Longitudinal section through a palm fruit and seed. The endosperm is homogeneous. The embryo is tiny, like a grain of rice.

Longitudinal section through a palm fruit and seed. The endosperm is ruminate (intruded by the seed coat). The embryo is tiny, like a grain of rice.

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 🌾🧪🌱

Photo of a fruit stand with mangoes, durians and mangosteens. An old school electronic calculator rests on the fruits.

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

A fan palm on the edge of the forest with deeply segmented leaves and inflorescences that tower 2 meters above the foliage.

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 🌾🧪

A clustering, shrubby palm with palmate leaves.

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 🌾🧪

A climbing pinnate palm, a rattan, with foliar climbing organs as described in the post.

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 🌾🧪

Small waterfalls among rocks.

A begonia with asymmetrical leaves and dark veins.

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 🌾🧪🌱

Fan palm with wedge-shaped segments.

New leaves that are red mottled with pink.

A bipinnately compound leaf whose leaflets are larger and broader at the tips of the rachises and smaller at the bases.

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 🌾🧪🌱

Clustering Palm with wide leaflets.

Clustering Palm with narrow leaflets.

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 🌾🧪🌱

Smilax vine. Leaves discolorous and pink new shoots. A hand turns over a leaf to show chalky white undersides.

Smilax vine. Leaves discolorous and pink new shoots. A hand turns over a leaf to show chalky white undersides.

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 🌾🧪🌱

Small fan palm with grouped segments.

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 🌾🧪🌱

Potted citrus loaded with small orange fruits

Potted citrus loaded with small orange fruits. Also a large golden Chrysanthemum.

A small banner saying “happy new year” in Vietnamese hanging among small orange fruits

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

Feel free to correct me! I am always grateful for help. 🤠

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

You’re absolutely correct! Slip of the fingers! Thanks for the correction 🙏🏻

Cecropia is fantastic, isn’t it?😄

Close-up photo of an array of large, deeply palmately lobed leaves. Each leaf has ca. 20 segments, which are shiny and spathulate.

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 🌾🧪🌱

Photo of two people standing in front of a large, sparsely branched tree with very large, lobed leaves.

Close-up photo of two isolated fruits next to a pen, for scale. The fruits are brownish and tessellated. They are multiple fruits, each is the product of many flowers that fuse together as the fruit develops.

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 🌾🧪🌱

Photo of the branches of a tree: POV looking up at the branches with the sky in the background. The leaves are large and deeply palmately lobed.

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 🌾🧪🌱