A “Hindsight is 2020” Series
By Justin Daniel, CNPS-San Diego President & Field Trips Chair and Grower & Collector
For part 1 click here For part 2 click here
We’ve gone over the quick, simplified discussion on ethical collecting practices to seed collection and processing methods for California Native plants in general over the past two months. Hopefully, anyone following along to this point has a number of favorite species in mind and likely already have the dried fruit or pods in a paper bag or have sorted and labeled the lots. If not, remember that leaving a collecting trip empty handed is not a bad thing in the grand scheme of things.
For species like California poppy you might have at this point realized they are both simple to collect and also surprisingly explosive (dehiscent). Dried fruits of Eschscholzia californica may ‘pop’ in your hand when you pull them off the stalk, scattering seeds everywhere and leaving you with the curled carpel ‘straw’. Once you get the mature green to browning pods into a loose paper bag to let them dry, you’ll find out over the next few days that they pop in the bag and do most of the sorting for you. Every year at this time, my dog becomes suspicious of all paper bags, eyeing them warily for the next pop. Once the bag finally calms, pour out the seeds through a colander and you have California poppy seeds ready to be stored in a cool, dry place, sown directly outside for next year, or shared with your neighborhood.
Below, fruit types are used to group genera and families that have similar collection and treatment methods. Where genera or families are not listed below and where exceptions apply, there are many great resources to help narrowyour focus. If the links below don’tprovide the answers you are looking for, become a member of the San Diego CNPS discussion group and join a wonderful community eager to answer questions. As a science based organization, your research, stories, pictures, and volunteer hours contribute mightily to our goals of better documenting and educating our neighbors about the intrigue and benefits of native flora. Here are some more great rabbit holes:
http://tchester.org/plants/index.html
http://www.sci.sdsu.edu/plants/plantsystematics/studentresources/PlantSystematicsLinksStruwe2011.pdf
https://www2.palomar.edu/users/warmstrong/termfr1.htm
To help differentiate and identify Families, and to focus then down into genera, follow this great guide:
If you cannot find seed on a healthy plant during the correct season, it may mean it is a male plant. Do your research and keep looking!
Dry, Hard Pods & Capsules
Some of the simplest seeds to collect are easy to find pods that dry on the plant. The fruit waits through the summer until winter storms, high winds, ravenous birds, or a periodic brushfire cracks them open. Snip or carefully break the cyme of the dry pods into a bag with site data and pics already noted. Avoid any that are molded, holed, or already ripped open by birds since these are likely to contain spores or insect larvae. Carefully check for worms, mites, ticks, spiders, and caterpillars, which are common. Processing is usually done with a mortar and pestle or by rubbing the pods vigorously between rubber soled sandals to break the pods and release the seeds when they are too tough for gloved or bare hands.
The dry pod producing plants are some of the most popular landscaping and nectar producing native plants and include (in no particular order): snapdragons (Antirrhinum), larkspur (Delphinium), beardtongues (Penstemon), bush penstemon (Keckiella), bee plant (Scrophularia), bladderpod (Peritoma), bignonia (Chilopsis), liveforever (Dudleya),
deerweed (Acmispon), ocotillo (Fouquieria), blazing star (Mentzelia),miner’s lettuce (Claytonia), paintbrush (Castilleja), monkeyflower (Diplacus), columbine (Aquilegia), oceanspray (Holodiscus), cottonwood (Populus), alum root (Heuchera), tobacco (Nicotiana), thornapple (Datura), violet (Viola), creosote (Larrea), cocklebur (Xanthium) & blue eyed grass (Sisrynchium).
Papery & Dehiscent Pods & Capsules
The main difference between hard pods and papery, thin seed pods is the texture and thickness of the pericarp. A few hard pods have mechanisms that“explode” when conditions are right.Timing is important with these genera and families because the mature seeds are only available for a limited period. Heat, herbivory, rain, wind, and dry conditions are factors for these fruits that trigger release of their seeds nearly all at once. Plan to check on and collect these within three to four weeks after blooming ends and always prior to a forecast for high wind or rain events. It may take extra visits, but if too late,you’ve likely missed the season entirely for that location. You may collectmature pods that haven’t opened yetand dry them in a paper bag, though the greener fruits will yield fewer mature seeds. Some genera are included here with samaras that fall away easy, like maple, often into a stream or pond. Some, like agave and yucca, produce fruits that are targets for larvae and may take all summer to dry completely. Others have seeds that easily fly away on parachute tufts, like milkweed. Others simply open when with the lightest touch, making collecting them a delicate exercise. Thankfully, once collected, these require very little processing or easy processing to clean them.
These include onion (Allium), milkweed (Asclepias), mustards (Brassicaceae), catchflys (Silene), morning glory (Calystegia), spurge (Euphorbiaceae), locoweed (Astragalus), buckbrush (Ceanothus), fairyduster (Calliandra), redbud (Cercis), lupine (Lupinus), pea (Lathyrus), palo verde (Parkinsonia), clover (Trifolium), vetch (Vicia), flax (Linum), mallow (Malvaceae), sand- verbena (Abronia), ash (Fraxinus), monkeyflower (Erythranthe), evening primrose, fuschia, & suncups (Onagraceae), peony (Paeonia), poppy (Papaveraceae), gilia (Gilia), maple/elder (Acer), iris (Iris), lilies (Liliaceae), orchid (Orchidaceae), brodiaea/blue dicks (Themidaceae), agave (Agave), yucca (Hesperoyucca), & beargrass (Nolina).
Cones
These gynosperms are fairly forgiving on timing since seeds can take months to several years to develop. Collectingdry cones from the tree isn’t always necessary, but preferred since dropped cones are immediately available for predation on the ground. Caution is advised in cases like Pinus coulteri, asthe cones are known as ‘widowmakers’for their ability to maim or kill when they drop from a great height. Cracking the dry cone is best done with pliers, but some open easier when placed in a low fire or allowed to dry in a low heat oven for a few hours or sunny windowsill for a few months. Use a solid box for these if taking the whole cone to avoid dropping pine sap.
Genera: pine (Pinus), juniper (Juniperus), cypress (Hesperocyparis), & cedar (Calocedrus).
Dry Berries / Drupes
These fruit dry with little fleshy interior tissue (mesocarp), though they are covered by a skin (pericarp) like a berry. Collect when the fruit changes color to bright red or yellow-orange. When pressed and rolled between the fingers, the skin tears and the seeds fall away, often neatly. While these genera can be processed while still wet, waiting until these are fully dry helps to avoid odors, astringent juice, and extra workseparating the seed from the ‘chaff’material. Many of the following genera also should be approached with caution given the spiny leaves in barberries, prickles on roses, and poisonous compounds found in most nightshades. Use appropriate gloves. The color of these berries entice natural herbivory by birds, so acid treatment can helpwith breaking dormancy, though I’ve found that isn’t required.
Genera: Barberry (Berberis), dogwood (Cornus), silk tassel (Garrya), wild rose (Rosa), & nightshade (Solanum)
Stone Fruit
Stone fruit here are nearly identical to dry berries and drupes except that the genera within Ericaceae have stones / nutlets that are either fused or free (a diagnostic characteristic). The seed resides protected within the hard shell that requires special treatment like heat/fire or acidic conditions to break dormancy. It is possible to speed the process by manually cracking the stones, but you will lose many viable seeds in this manner. These ‘seeds’ aremost often sold as untreated, intact nutlets. Collect when bright red or brown. Withered fruit is fine to collect, but difficult to process.
Genera: Manzanita (Arctostaphylos),mission manzanita (Xylococcus), & summer holly (Comarostaphylos).
Fleshy Fruit & Berries
These genera and families listed below have seeds covered by moist fleshy tissue and a thin skin or leathery rind,and here you’ll find the most delectablenative fruit. Not all are edible, despitetheir cousins being found on grocer’sdisplays. Collect by hand or tongs when ripe. These are separated from dry fruits because they are much easier to process while wet. Forming a mash under water and straining the pulp away does wonders to separate these seeds. Gloves and sometimes tongs and masks are best used to harvest and process these. A small amount of liquid soap helps the washing process, though the separated seed should be completely rinsed and allowed to dry completely afterwards. Caution ought to be taken when harvesting bush rue / spice bush since it contains phytophototoxic oil compounds that develop a rash on sensitive skin when affected areas are exposed to the sun.
Genera & families: Cactus (Cactaceae), hackberry (Celtis), honeysuckle (Lonicera), snowberry (Symphoricarpus), gourds (Cucurbitaceae), gooseberry (Ribes), coffeeberry (Frangula), lemonade & sugarbush (Rhus), redberry (Rhamnus), strawberry (Fragaria), toyon (Heteromeles), cherry/apricot/almond
(Prunus), blackberry (Rubus), bush rue (Cneoridium)*, desert thorn (Lycium), ground-cherry (Physalis), grape (Vitis), palm (Arecaceae).
Asters
The massive family of Asteraceae contains just over 100 known genera within San Diego County alone. The compound inflorescence produces copious amount of dry nuts per head and many have a light fluff attached (pappus), which helps them to disperse in the wind. Exceptions here are bur-sage/ragweed (Ambrosia) and cocklebur (Xanthium), since they are treated better under other type descriptions here.
Collect the seeds after the head has begun to dry and the seed pulls freely from the receptacle. Place all of it into a large paper bag. Tarplants and other glandular species are sticky, so thin gloves are recommended duringharvest. Separating the ‘seed’ fromthe chaff can be done with a light mashing between the hands to allow the fluff and seeds to fall into a bowl or tray. Blowing the collected mess with the correct pressure helps to separateit, though you’ll have to experiment onwhat works best. Many final seed products will contain chaff as an unavoidable byproduct. Static electricity can help the process along by rubbing a plastic sheet with a cloth to create a charge. Overall, astersdon’t need a wash for cleaning, butthey will need to be free of larvae and mold.
Acorns & Hard Nuts
These are staples of the ethnobotanical diet, loved by people and squirrels alike. Collect when mature and dry on the tree by hand or basket, or when green but has signs of changing color. Picking them up off the ground results in more failures given they are attacked by insects, mold, and rodents quickly after falling. The few that survive on the groundcreate more trees naturally, so it’s bestto leave these alone unless the ones on the trees are simply too difficult to reach. Toss those acorns that have visible holes or float to the top of a shallow bath. For walnuts, remove the leathery rind, which should easily split from the nut by hand with little effort when ready for planting. Jojoba contains a waxy oil found to be very useful as a commercial product and the seed inside is edible with cooking.
Genera: Oaks (Quercus), walnut (Juglans), & jojoba (Simmondsia).
Loose to compact achenes and grains
This last category is a bit of a catch-all, but are collected and processed in the same manner. The important things to remember when collecting and processing these families and genera is that some contain poisonous compounds, skin and mucus membrane irritants, spiny/Velcro-like inflorescence parts, and/or strong residual odors. All will leave an awful mess after processing. Borage family often has fine hairs. Celery family are often poisonous, difficult to ID, and can have obnoxious burs. The monocots here are particularly tough to ID, especially without all the parts of the plant.
Collect the whole inflorescence stalk (cyme) or panicle in the field when dry. Use caution on those like pitcher sage as the seed can easily be knocked free and lost if handled too roughly. Test a cyme in your glove or hand by gently crushing the lot and sifting for seed. During processing, nearly all can be lightly crushed with gloves or hands or between two rubber sandal soles to make a dry aggregate that frees the seed from any attachments. The correct pressure is species specific, especially with grains. Screen the mixture to separate the fine dust and irritating fluff, seeds, sticks, and remaining flower parts. A magnifying glass is very useful for determining if the processing is working effectively on species that produce very small seeds, like spineflowers. A vacuum, mask, and moist towels are quite handy if processing indoors. For those seeds with tails, you can break the tails off by hand, but they fall away easily enough when gently crushed too.
Genera & families: Celery/carrot family (Apiaceae), sage (Salvia), borage family (Boraginaceae), saltbush (Atriplex), goosefoot (Chenopodium), pitcher sage (Lepechinia), mountain mint (Monardella), bluecurls (Trichostema), ragweed (Ambrosia), skullcap (Scutellaria), wishbone bush (Mirabilis), sycamore (Platanus), linanthus (Leptosiphon), buckwheat (Eriogonum), spineflower (Chorizanthe), virgin’s bower (Clematis), mountain mahogany (Cercocarpus), chamise & redshanks (Adenostoma), bedstraw (Galium), willow (Salix), vervain (Verbena), sedge (Cyperaceae), rush (Juncus), grass (Poaceae), & cattail (Typha).
Please share your findings and help toround out collecting knowledge. I’veleft out uncommon genera for thenursery trade, so if you don’t seesomething you are looking for, as a Genera or Family, please ask! The more we know as a Society, the more we can refine our efforts to reduce waste all around.